I am somewhat intrigued by Paul's recent confession in his review about Zeugma - "I always travel with out-of-date guide books". There must be a story in there!

Personally I think that guidebooks are something of the past. I still do buy them sometimes, but most are gathering dust in my bookcase.
For my recent Balkan trip I bought Bradt's Guide to Albania, and downloaded the Pdf's of the Lonely Planet about Macedonia and Kosovo. The latter two were a waste of money, so badly researched and out-of-date. The 14 pages (including front page and index!) on Kosovo only covered Pristina and a glimpse of Prizren. I do like the Bradt guides better in terms of the introduction of a country, but their maps aren't so good and the practical information usually isn't enough to get anywhere.

What usually works for me nowadays is:
- read AB evaluation and (part of) nomination dossier of the WHS that I want to visit, and write down notes about significant landmarks
- search the internet for a clear map of the city/town/area
- search the internet for trip reports of people who have been there recently, and included practical info about getting there (important when you mostly rely on public transport) and opening times/special entry requirements
I print it all and bundle it into my own 'guide' per destination. Has the advantage of saving space and weight in my backpack!

Which guidebooks or alternatives do you use for WH related trips?

I have been meaning to write one about this for ages. So thanks, if you could do the one I have been meaning to write on podcasts as well then even better :)!

For me I still use hard copy guidebooks, I like reading them on my commute and they are a nice way of doing a bit of imaginary travelling. Though I will admit, I now probably get more of my travel itinerary via online resources.

Here is my personal rundown of the ones I have used.

Looking through by travel bookshelf it is fairly obvious to see that Lonely Planet is my default guide. They feel mostly intuitive to use and pretty comprehensive. I really like their Encounters City guides even if their post 2011 versions haven't been an improvement.
Though there is quite a bit of diversity in their range, and since their overhaul in 2011 I think their maps aren't very good, and actually quite difficult to use in the field.

Rough Guides have probably become my favourite now, they have always been a little better on some aspects (background and history) and now their maps are superior to any other available guidebook. Their map of Fez Medina alone deserves an award for making the maze readable. Again though there is quite a range, their Thailand one I used in 2010 was useless.

Footprint found them to be interesting reads on Latin America. Was pretty good when I finally got to test drive it in Brazil last month.

Bradt best for off the beaten track locations (the only one that had a Belarus specific guide when we went there). Can be exceptionally informative without straying too far into dusty academic prose. Maps are very basic.

Cadogan like a slightly dotty version of Bradt. I actually rather like them and the maps are better.

Michelin I like the three star rating system, but beyond that I find them rather awkward and dry to use. Arranging things in alphabetical order doesn't work for me.

DK not really any practical use when travelling, and aimed at a slightly different style of traveller than the users of this forum. Can be a handy for a swift intro to somewhere completely new, but mostly lack detail.

Blue Guides the complete other end of the scale from DK, can be very enlightening, very high brow and more than a little dull. If you want to know full details about every case in an internationally renowned gallery these are the ones to aim for, though sometimes it is tough to see the wood for the trees. If you just want an overview best to head elsewhere.

Time Out have limited coverage of a few big cities, but can be really good, especially on non-sight seeing activities. They don't get updated that regularly though, and a lot of their listings are prone to becoming out of date quickly.

Moon my first attempt to use it wasn't great, their South Korean guide I found to be unintuitive and just not really what I needed, I ended up stuffing it in the bottom of my pack after a couple of days and never going back to it. However, we used them for Mexico City and San Miguel, Querataro & Guanajuato and they were pretty good.

Let's Go I was given a copy of their Europe guidebook whilst in a hostel. It was dreadful and I ended up 'donating' it to another hostel's bookshelf a few days later.

Rick Steve's I find them kind of quaint, the maps are dreadful, but it is sort of interesting to see what things American tourists need to know about places. Reading through the cultural tips in his London guide is rather enjoyable.

And of the non standard ones:
Use It aimed squarely at younger and student travellers, so I think I have moved out of their audience, I found them to be brilliant, the focus is on food, drink and activities but they are made by local students so it gives a great local insight. The highlights of Warsaw came from these guides. They even have an Olomouc one now, bound to win me over.

In your pocket again really useful as they are written by locals, exceptionally good for cities in Central and Eastern Europe that aren't covered by the traditional publishers (there isn't a Rough Guide to Minsk, or Lonely Planet Gdansk) They do have adverts in them, but then they are free, so it is a decent compromise if you ask me.

Personally, I still use Lonely Planet if there is a current edition out there. It covers my basic needs, specifically public transport options. It has its shortcomings, but I guess any book does. In the end, I have come to see my travel needs as very specific and hard to cover by a book. It always comes down to online research, e.g. here.

What I have come to appreciate A LOT is buying a PDF instead of the paper edition. Apart from being cheaper, it also comes in quite handy as I don't have to carry a heavy book around just to look up stuff. I just look at my smartphone which I take anywhere I go. This also has the added benefit that I don't look like a lost tourist, but like your average local staring too much at his smartphone. ;)

Whilst moving in recent years to a mixture of "paper" and "electronic" assistance when travelling I wouldn't like to have no Guide book at all.
a. Even in UK I am not prepared to pay for 3G access and use a SIM with a free monthly limited access 3G service from my home broadband supplier - and certainly not for overseas roaming! Buying a local SIM is also a hassle and potentially costly in relation to our likely benefit
b. I don't want to carry around anything larger than an iPod or smart phone so that limits screen sizes and I don't want to be constantly having to move around pages on a screen when out and about any more than is absolutely necessary
c. So I am reliant on pre-downloads and Wifi for access to "electronic material". Countries vary considerably in their provision of free wifi. In UK one knows the chains where it is available but Hotels are often still "behind the times". Travelodge - our normal "chain" hotel - still only provides 30 mins free in 24 hours. I was impressed recently in Turkey that all our hotels had free unlimited wifi with good connections (but I guess that comes from only booking hotels from the Web!) – other recent trips to Pakistan and Nagaland were not so good! But in Europe a number of chains (E.g McDs) operate the system by which you have to receive a code by mobile to use their wifi – which, as above, we don't have!! I remember a few years ago in a Costa Coffee in Shanghai one of the lady servers kindly let us use her mobile to obtain the code!
d. We normally travel with a rent-a-car ( sometimes with driver in "3rd world") so the extra weight of a guide book isn't really an issue – and it stays in the car if not wanted which is probably more often than not when we are away from the car. We also don't need a guide book which is good on transport, hotel or restaurant details.
e. We rarely have completely pre-determined route so are unlikely to have pre-downloaded everything we might find useful
f. I like books as physical objects and can't bring myself to "pay" for ephemeral Ebook material. I want the book for easy reference before, during and after. It is a souvenir of the trip with its scribbles and grubby pages bringing back memories of places and events! A lot of my guidebooks are bought second hand several years before I might actually make a trip to the country – which explains the issue of "up to dateness". But the things I am wanting them for are not likely to be the things which change (despite the Zeugma experience!). I also like to have sets of several series of guides in my library for access "at random". (I have pretty full sets of LP, Michelin, APA, Eyewitness and less so of Bradt, Rough and Footprint. Plus "historic" sets such as Baedeker and Bleu - the former very useful if you want to know where to water your horses and feed your servants!)

So – what DO we use?
a. A lot of material pre downloaded to Dropbox (and Evernote particularly for Web snips) and then to our handheld device. These have to be fully downloaded to the device as they can't otherwise be accessed "on the road" without wifi/3G. This material is likely to cover a lot of "snipped" Google maps of routes and towns together with PDFs from e.g UNESCO and snipped web pages of site opening times etc – all foldered by town and site. This is likely to be added to during a trip when in our hotel and planning the next day – eg the next night's hotel details and map. It may seem counter-intuitive given that I am prepared to carry paper in the form of books but I can't usually be bothered to print down much of this material!
b. I am prepared to carry 2 guidebooks (but there are 2 of us - so my wife can take one!!) – usually this will be an LP, plus 1 other which needs to complement rather than duplicate LP. This often means Michelin if in Europe. Unlike Meltwaterfalls I rather like the DK Eyewitness series for its drawings and descriptions of sites.
c. A fully downloaded Sat nav map. This for us is a new technique – first used a few weeks ago in Turkey with great success. Sygic is free as an app and also for its maps. Ok you lose some features such as speed warnings etc but that is not important to us. So our Android device has a downloaded fully detailed map of anywhere in the country and the ability to guide along a route using only "Location" and with no need for 3G or wifi. Again, we are not prepared to pay the car rental company for in-car Sat Nav – and having the map downloaded to our Android device means it can also be used when city walking. Despite this I still like to have a guide book sketch map and find that LP's "style" is the best compromise between detail, accuracy and ease of use. (Though as most of my version are pre the 2011 "improvements" I don't feel able to comment on the assessment of these by Meltwaterfalls!)

Like Els, I think guidebooks are an outdated form of travel information. I still buy them though (LP is also my favourite), but rather as a decoration for my home. As I work in e-commerce I'm probably too much online framed. But here's how I do it:

Travel preparation
My sources are all online: the reviews from this site, unesco.org, TripAdvisor (for restaurants), booking.com (for hotels), mietwagen.check24.de (for rental cars), the official pages of the WHS I want to visit and official tourist sites of the places I want to visit. I prepare my route with google maps, as there route suggestions and travel times always turned out to be pretty accurate. I download cities or regions from google maps onto my mobile phone for offline use. I also download whole cites in the TripAdvisor app for offline use. The come complete with map and help a lot to find a restaurant or a sight. A offline map in combination with GPS is such an improvement compared to the mostly outdated, sometimes inaccurate and not very detailed maps in a guidebook. This should really be a standard tool for any traveller.

During the trip
My travel companions are usually my mobile phone and a laptop. Further, I bring my personal nav system whenever I rent a car. During the trip free WIFI is really important for me. It's a killer criterion when selecting a hotel. There I use the laptop, to adjust the planning, save my pictures and update my documentation. I don't count on WIFI when on the road, but big chains like McD or Starbucks (even though I don't drink coffee) are a reliable source for free WIFI. And finally, sometimes I use my most archaic tool: asking people on the street :)

Btw, nice tip with Sygic, solivagant. But this app seems to be too large for my phone. More than 7 GB? Couldn't download it due to lack of space.

I just don't recognise such figures or anything anywhere near them! This is the Sygic page setting out the storage requirements -150mb -mine says it is using 87.
http://help.sygic.com/hc/en-us/articles/202261838-Compatibility-Requirements
As I said I wouldn't have any smart phone which didn't allow an SD card so goodbye iPhone and the latest Galaxy - not that i would be prepared to pay for either of them. Thanks to Herren Karl and Theo Albrecht mine cost a mere £40 (55 Euro.)

If only every UNESCO site had a guidebook like Regensburg.

I just don't recognise such figures or anything anywhere near them! This is the Sygic page setting out the storage requirements -150mb -mine says it is using 87.
my bad. my phone is somehow messed up.