This isn't a book to take out with you bird-watching, as it is large and heavy. It's a book to look at before you go or refer to when you come home. Perfect for taking on holiday, too. It's ideal for using with children. I would say it for the interested amateur rather than the dead-keen birdwatcher.
The entry for each bird is very informative, often a full page. Pictures from all sorts of angles, maps, notes on telling apart similar species, a nice bit of text on the habits and ecology of the species. The illustrations are very beautiful. There are comparison sheets showing related species such as ducks side by side.
As well as the actual ID guide for birds, there are many pages of fascinating background. At the front, essays on evolution and anatomy, and pages on particular families of birds such as "Larks, pipits and wagtails" are followed by a splendid section on habitats - "Mountains and moorlands", "Lakes and gravel pits" and so on. Then at the end there is a large and really excellent guide to places for bird-watching, not just reserves but a whole range of places arranged by region with maps and evocative photographs.
Buy this inspiring book for yourself - it would also be an excellent gift for anyone starting get interested in wildlife, or for someone you WANT to get interested in wildlife!