Painting Alluminum Rims??

Hey guys, I am wanting to play around with a paint skeem on my rims until i can afford a set of 18's that i want.....I have 16" AR bullett hole wheels right now. I am thinking i want to paint the center of the wheel black and leave the cap and the lip of the rim alluminum....how can i go by doing this? Should I sand them down a little then buy some auto spray paint and cover them? Do any of yall have experience doing this, i don't want to spend to much but want them to look nice and last a while until i can purchase my 18's.....Thanks!!!