AFK Cloaking is more of an economic PvP than traditional PvP. Generally, an AFK Cloaker will go into a system where the enemies are trying to make money through ratting and sit somewhere cloaked so they are unable to be detected except through local. During the stay in the system the AFK Cloaker may actually be afk or may be sitting as his computer waiting for the enemy to let their guard down and then he strikes.
An AFK cloaking fleet is fairly simple:
You can decide how active you want to be. 1 or 2 people can go afk for hours together and then come back and do a bit more ganking, but this would be harder to organize with larger fleets. Larger fleets can lay down some serious firepower on a shorter term, though. Launching probes (every hour or so) will help you track people and make your presence felt. You can also fake trying to look active using probes, and then kill people once they get confident that you're only trying to look active.
AFK Cloaking is not a job for the impatient. This is a job that requires dedication, patience, and critical thinking. You must give a false sense of security to your opponent. You must observe their behavior, their habits, their reactions. If any role in Eve is a hunter, this is it.