Good luck

. I doubt you'll find one in a book store or online; I doubt one even exists in the way you would like it to.
The attached file is, I believe, teaching notes from a class. Some one was teaching a class using RobotC and compiled his notes into a single document. It is by no means all encompassing and only covers the basics, but it is printable. The original link is buried somewhere in these forums but I don't remember where and it's not worth hunting for it.
To the best of my knowledge, no book has ever been written for RobotC, it's just not "big" enough yet. Besides they can't even get their own documentation in order, what makes you think they have a book. No, this pdf is the closest you will come, sorry. If you need help, these forums are the best place; 95% of the time you will get the answer, or at least some help.