I'm getting ready to paint my ped. I searched on the forum and found some great information. I decided to do a little more homework though. The general consensus is that if you're going down to bare metal, then you need to use a metal prep first. This usually comes in the form of phosphoric acid. Duplicolor sells a prep spray for this specific purpose. After the acid wipe down, you will need to use an acid etching epoxy primer. from there you need to sand to a rough surface (mainly over any places where you will use filler) apply your filler, and then apply a sandable/filler primer. color. clear coat.
this pdf lists duplicolor's suggested methods for painting. I find it quite usefull and thorough, listing dry times and sanding grits/methods.