I bought this one, along withe another (Sterling Flatware Identification & Value Guide) for my mom and she uses it a lot. I think she uses the other one more but she always has both on hand. It has a lot of good info on how to id a piece, great pictures of hallmarks etc.
This book is a must have if you collect antique English silver. If you only want one book on the subject this is it. If you collect American or European silver, this book would not be my first choice. You can't get more info on antique English silver including hallmarks, history, and the different pieces of flatware and holloware that were made with any other Silver book I have ever read.