You should be able to kill the engine by turning in the idle mix screws. If you can't the engine is running on the transition circuit because the throttle is too far open at idle (or you have a fuel leak into the intake manifold). Leaning out the idle by installing a larger air bleed will also lean out the transition circuit (low speed, just off idle).

Instead of buying one or more books I suggest doing your research online. In my experience, most books are filled with fluff and just tell you do tune jets, pumps, squirters and such but never get into the real good stuff. And if those basic tuning tools aren't enough most authors suggest getting a different carburetor. You can do better. The Edelbrock site used to have a fairly extensive tuning guide for their AFBs, Holley may have something as well. Your best source is internet forums, just don't accept the first things you read, read a lot and look for some sort of overall consensus before diving in. You don't need to ask questions, most have already been asked and answered before in many forums out there. Maybe just start a thread here regarding the tuning sequence for your particular carburetor.