Geeze you just reminded me of something. When I worked at Entercom, we had something that I think was called a "rules service", which I haven't seen since I left there. It was like those old recipe packs mom used to subscribe to with the three-ring binder. She'd get a pack in the mail once a month and put them in, and then when she was done, the binder would sit in a box in the garage with the bedazzler, the cookie gun, and the closet organizing gizmos.
That being said, I was looking for a more practical answer like "things to watch out for that the FCC man will gitcha for". And I'm not being a total nitwit about it; things like having directional arrays that are pointing in the right direction, and a transmitter that's on the right frequency are usually a good place to start. ;-)