I would agree with poweder coating rather than painting,
but if you want to paint them, here are some good instructions:
What you need:
4-6 cans of Rustoleum Black Night Metallic Paint
1-2 cans of Rustoleum White Primer
1 can of Rustoleum or other brand clear coat
1-2 large rolls of masking tape
1 8 sheet package of fine grit sandpaper
1 Jack and 2 Jackstands
Estimated Time: Around 4 hours
Remove wheels from car it is easier to do 2 at a time so jackstands will be needed.
Wash them with some water and soap until all dirt is gone, then dry completely.
Use a fine sandpaper and sand down all surfaces to be painted. You need
to get rid of the clear coat. If silver they should become a powdery looking silver/whitish color.
Mask off the tire and all places that you do not want painted.
Use a white primer, it makes it easier to see where you have already painted. Apply 2-3
coats and let dry completely between coats.
Apply 4+ coats of paint making sure to use light layers at first and then build up to the full
coats for an even finish for the last couple coats. Make sure to let them dry thourghly between coats.
After the paint is dry, apply 2 coats of clear coat for extra protection.
Allow to dry for about 30-45 mins before re-applying to the car.
Repeat for the other three wheels.