get spray primer, spray wheel paint, and normal clear coat, and 300-400grit sand paper
sand down the wheels to get the clearcoat off of them, and give the primer something to attatch to, then i put 1 real light coat of primer, sanded that, then a normal coat of primer over that, and sanded till it was perfectly smooth.
then i applied 1 light coat, and 2 normal coats of paint, then 2 coats of clear
BTW: the spray can will say how long to wait to spray anything ontop of the paint, which includes more coats of the paint
EDIT: to keep paint off the tires i put cards between the rim & tire. that worked real good. and when you are spraying the paint/primer/clear, make sure you start spraying before your close to the rim, and make everything even
I had to redo one rim, kuz i started spraying on the rim instead of spraying away, and moving the spray across