You strip all the old paint off, sand, fix all the dents and imperfections, primer the car, tape off everything you dont want painted, and drop it off at Maaco.
My friend had his car painted there, but all of the prep work was done be a professional body man. It didnt look bad at all when it was done. Again though, the prep work was done by a professional.
Like Clark said, you get what you pay for.
Honestly, I would recomend taking it to Rolla. Great work done on the cheap.
-Marc