I agree with Trucky1008 as Paul Kirk's Championship Barbeque Sauces is an excellent book. I've made dozens of my own sauces and rubs to great accolades from my friends and family. Paul Kirk's has helped me create many of them.
I also enjoy experimenting off his and other recipes. A litle trial and error is fun. Jack Daniels has seemed to find its way into a few of my sauces.