The down side with this book is that I bought mine in January 2006 and at that time was right up to date (for patch 1.8) but now we are several versions down the line (patch 1.10) some of the content of my book is inaccurate.
So buy all means buy this book for what it is - a strategy GUIDE, but dont expect a bible to live, work and play by - it wont stay in date for long.
Obvious ommissions are the lack of instance maps. Great pluses are the price lists for items - so you dont get ripped off at the aucion house and the first day walkthroughs to help you find your feet. Spell and ability descriptions are great too.
The detail is great but beware as WOW evolved this book is getting out of date. Its sits on my desk next to the computer and helps power leveling. Some might consider this cheating - I think road map is a better description.
Go on treat yourself - you wont regret it! If you see me on line say hi.
Sure you can use Thottbot and the info may be more detailed in places but unless you have 2 screens or don't mind alt tabbing out of the game it's a damn sight more convenient to have a book next to you.