If you're only concerned about keeping the frame material in good condition, it doesn't matter if it's rattle-can-painted or not. Just sand it down to bare metal. Wipe it down with alcohol and prime it. Wait 24 hrs. *Wet sand it with very fine grit. Prime it again. Wait 24 hrs. * Wet sand it with very fine grit. Wipe it down with alcohol. Then use Rustoleum paint and paint it. Wipe it down with alcohol and paint it again after another 24 hrs. Wait three days, then you can ride!
If you use dull black paint, you can just wipe it down with alcohol and touch it up every 6 months or so.
* If you use textured spray paint, you can skip the wet sanding!
(See post #13 instead, it's even better)
If you seriously want it to look really good and the paint not to chip, the best way to go would be with powder-coating!
Good Luck!
