The books noted in the previous posts are all good. I have them and use as a starting point. The first thing I ever smoked was a butt and it came out pretty darn good. Get a Thermapen and take notes for all cooks. Stay away from making your own rubs unless you use something simple. One of the most important things in my opinion is grill and food temp. Know when to take off the meat.
Bubba Keg / Stumps Baby / Super Fast Yellow Thermapen / Lodge Cast Iron Grill / Smoke Vault