Very nice. I always try to resist buying such guides until I'm played a game a lot first, otherwise it is so tempting to read things in the book before you have seen or discovered them in the actual game, and that can really ruin some nice (or bad) surprises in a game's story/plot or environment. And I think that is very much the case in Fallout 3 where you discover something new in every area you visit that is different.