Darrell Young's D7000 guide is very popular and highly rated. Another one is Thom Hogan's "Complete Guide To The Nikon D7000".
I have been very happy with Thom Hogan's 820 page book/guide. It is very detailed in all aspects of using the D7000. Everything is discussed such as its history, myths, features, settings, usage, recommendations for all settings, many features are compared to other Nikon cameras, etc. Even the SB400 through SB900 Speedlights and their usage are discussed in detail.
It's a little expensive if you order his complete package (includes printed, PDF, and ebook versions and a smaller "To Go" condensed “field guide”). I highly recommend at least buying the book/guide in printed form. You will be surprised how many times you grab it off the book shelf for quick reference.
It is sold only through his website, the link is below.