I don't remember name of the book that i have, it is for 1.4 cerification, something about Sammy's DVD.
I liked the book but it can't tell that it had big impact on my assignment. I remember they had rather nice
thread overview saying that very unlikely we'll need to do anything of this complexity for the assignment whereas i found threading for the assignment much more difficult than their overview.
I found this forum much more useful than any book and i joined here only at the end of my development, better be earlier.
I think one book would be enough for you, better save money for somehing more useful, icecream or beer for example.