My friend and I went backpacking through Europe for almost six months, visiting almost 40 countries, and this was practically our Bible at that time.
Suggestions for accomodation, sightseeing, food, bars, cafes and restaurants, and activities; in addition to useful information about the country, the particular city you were visiting, history, and some basic facts and info about things like currency, visa, how to get around, how to get into or out of wherever, prices, maps, and other useful information.
We often used this book to find out how to get somewhere, what places and cities to visit, and where to find hostels. It's quite a big book, so it's rather heavy to carry around, so we'd find a hostel, decide on what to see in the city based off the book and the maps we could get at the hostel.
Very useful for travelling to several countries in one go, and the descriptions and tips are witty and helpful.
Will definately get one for the next continent we'll be packbacking in!