Two words... "Slap it!" Tony Oppenheim
http://www.slapit.com/
This book is what I used years ago to learn the mysterious world of slappin' and poppin' - it is very easy to understand with this book. And back when I bought the book it came with, what at the time was a state-of-the-art teaching aid - a sound page! Now I don't know how old you are, but in the old days, before CD's and MP3's we used to use this thing that the rappers and DJ's use today, called a 'turntable' to play our 'records' on... This sound page was a flimsy, vinyl, square 45 that let me hear these exercises as I was reading the notes... All the differnce in the world! Get 'Slap it!' today and I promise you, next week you will be slappin' and poppin' like a pro!
--tz