46 countries, 1338 pages - for a tenner it's a bargain. An absolutely essential and reassuring companion if you're planning a big trip around Europe. You might be better off with the more specific country/region books Lonely Planet do if you're planning something shorter - a cancelled bus meant I ended up in Podgorice in Montenegro and there was sod all in the way of help. Saying that, it's hard to see how this book could be bettered when you consider the amount of countries it covers for its size and price.
Personally I find Lonely Planet books brilliant for cultural nouse, history and the best things to do/see but, from experience, a lot of hostels and restaurants tend to hike their prices up when they find out they've been added to it. So, have a look at the hostelworld.com reviews for places to stay and ask the locals for the best places to eat and you'll do well.
So - brillaint for sights, maps, directions, cultural background and the history of the countries you'll visit, sound for transport info (can sometimes be a bit vague with areas to catch buses and always check the train/bus times locally as they're always changing). Shop around for accomodation and places to eat.
Oh and there's a brief yes/no/hello/goodbye/please/thank you/I don't understand/where are the toilets? phrasebook at the back that I nearly missed.