Having not read widely on the subject I can't say this is the best but another book would have to go some way to beat it.
Good points - very accessible (alphabetical listing of tasks, setting, applications and tools), concise, comprehensive and well laid out. I was new to XP before reading the book and I found it very easy to understand.
Things that are OK but could be improved - the chapter on 'The Command Prompt' is very useful but doesn't quite live up to the 'complete documentation' claim made on the first page. As a scripting novice some more information on syntax would have been useful.
Bad points - littered with mistakes (particularly 'Figures' that don't show what the text says they should). This is annoying and downgraded my rating from 5 to 4 stars.
The book is great value and I got a great deal of stuff from it that I could go and apply. I would certainly recommend it but would suggest a 'corrected' edition if one exists.