Though there are options a-plenty, I would estimate there are about 10-15 really reliable travel guide series out there covering most marjor cities and countries of the world. They range from in-depth trade-paperback volumes to little pocket guides thinner than your wallet. And like reading any other type of books, everyone will have a different preference. When you first flip through a guidebook, there should be photos, passages, descriptions etc. that immediately grab you, if you don't know anything about your destination and you're already disinterested in the book, it might be a sign to try another. Different series also have different formats and target different interests, sometimes it's useful to have more than one guidebook for each destination. You may choose a more traditional sight-seeing series of books but then supplement with another series that highlights modern architecture for instance (or get your supplementary info online, which is what I do more and more).
I have a few favourite series that I always turn to first, and they rarely fail me. For the most info crammed into the smallest volume, get yourself a Mini Rough Guide. Rough Guides provide extensive travel information but not exclusively so, they also provide many different types of reference guides (ie. Cult Films, Football, and my favourite out-of-print volumes on House and Jungle Music!) Mini Rough Guides will fit easily into your average purse or jacket pocket and are packed with info for every destination, typically broken down by geographic area (cities/neighborhoods/etc). The first couple chapters will include the essentials - how to get there, transportation, languages, important things to know, then subsequent chapters cover the tourist highlights. Each chapter will begin with an intro including the lay of the land, then provide details of the major attractions moving into the lesser known spots. I find Rough Guides most useful when I'm in a country/city for an extended period (ie. one week or more) and really want to get into the thick of things. When I'm blowing through a city in 2-3 days, I'm only looking for the best of the best and this is when I find too much of the info goes to waste. The only other complaint I have about the Rough Guide series is that it lacks colour photos, and photos in general compared to other series. Trust me, when you're in a foreign land eyeing a non-English sign hesitantly, wondering if this is the building you're looking for or not... a photo really comes in handy!
About 4 years ago I was in a bookstore perusing guidebooks for New York City, it was my second visit and I was taking someone on their first visit so I wanted to get things right. The sales associate I chatted with recommended the Frommer's Day by Day series to me. The layout is unique in that it provides suggested all-day itineraries. In other words, they've done a lot of the thinking and planning for you when it comes to grouping things together geographically, picking the best stuff, and maximizing you time. For example, they provide an itinerary for best of NYC in one day, three days, etc. So if you have one day in NYC, this is what you need to see, if you have more time, then you can add these things, and so on... They also have itineraries grouped by interests, ie. Best art museums in a day. I think this is really as close to having a tour guide (without actually having a tour guide) as you can get. I did buy this guidebook, but admittedly I don't think I really stuck to any of the itinerarys, logical as they were. I would definitely consider purchasing this type of guide for another city sometime, I figure if there is a destination in the recommended itinerary that I'm not interested in, I can always pick an alternative spot or use that as shopping time!
In recent years, I've started taking trips that involve more cities, but fewer days at each. At first I was still using the Mini Rough Guide, but that's a lot to read just for a 2-day stop. Then I met up with my friend Stephen in London for a pint one night, and he brought me his copy of Top 10 Barcelona from the Eyewitness Top 10 Travel Guide series. Turns out it was exactly what I needed. It's concise, has photos, lists just the facts, a pull-out map, all in one slim volume. Perfect for any trip under 5 days (note: there's usually enough in the books for a solid 4 days of sightseeing, but it was borderline for my recent trip to Russia. On the last day in each city I was a little low on high/medium priority destinations, perhaps I should've taken the time to read a Rough Guide for more alternatives). Maybe it has to do with me being a sucker for lists, but the format is great for my needs. Each book begins with the Top 10 things to see/do, then gives a 2 page run-down of each of those destinations (I find I'm typically interested in about 8 of the 10 highlighted). After that every category is broken down in list of 10's, ie. Top 10 Churches to See, Top 10 Places to Shop, 10 Things to Avoid, and so it continues with sights, suggestions, info, and tips. In later lists you will also find breakdowns by neighborhood and suggested itineraries within these areas. It's worth noting how the way information is presented can make a huge difference, these lists are right up my alley, but I find the regular DK Eyewitness guides largely dull and unreadable.
Though I stick to the website, a lot of people seem to find the Lonely Planet series of guide books pretty helpful. I've been given one or two but have yet to read them. I also own a Style City guide for London, as the series title alludes, the imagery is chic, and some of the places they describe are cool. Overall though, I find the book impractical as it's missing all the essentials, this is a prime example of a supplementary guide book. Of course I would also consider Douglas Coupland's City of Glass a good supplementary guide book for Vancouver :) The other series I've experimented with but never got hooked on was the City Walks decks, each is like a deck of oversized flash cards with a map and description of the things you will see along the way. A great idea, but the lack of landmark photos and relatively short distance of each walk (before having to rummage for the next card in the deck in order to continue on) made it all a little cumbersome and confusing.
New guides, travel websites, and even travel apps are popping up daily and making it much easier to get info on the fly. But sometimes when the wifi's spotty and your roaming bill is almost as much as your plane ticket, there's nothing like a good old-fashioned, realiable, offline, printed book. So make sure to bring a good one with you!
