I suggest introductory survey papers by Axtell and/or Epstein (one is accessible through a link), "Simulation for the social scientist" by Nigel Gilbert, so to start. If you're interested in an informatics perspective I've also authored a paper in JASSS (also linked) and held a tutorial in a summer school a few years ago (slides on slideshare).
I'd say that deeper discussions depend on the kind of context you want to study with agent-based modeling...
My favorite is "An Introduction to Agent-Based Modeling: Modeling Natural, Social, and Engineered Complex Systems with NetLogo." It's really useful if you are using NetLogo.