http://www.amazon.com/Whats-Happening-Me-Guide-Puberty/dp/0818403128/ref=sr_1_1?s=books&ie=UTF8&qid=1362069422&sr=1-1&keywords=what%27s+happening+to+me I have heard that this book is really great at explaining these kinds of things to kids. Good luck!!
I don't know why that didn't link up. It's a book called "What's Happening to Me? A Guide to Puberty" by Peter Mayle.
Gimme some love and tell me what you think! No really, I can take it. I'll just double-up on those anti-depressants first. I may not be able to reply back quickly (I am a mom after all), but I read each and every word you type!