Just a little FYI... Autobody101.com is a great do it yourself paint forum.. I just got done repainting my entire car and it was the first one i have ever attempted. I learned ALOT from that site. There is good info on this site as well, but autobody101 is full of people that do this everyday.
I would also agree that there is no reason to sand through the clearcoat into the paint. If your going to prime everything anyway, then just scuff up whatever surface you are painting on. Make dang sure that the surface to recieve paint is cleaned with wax and grease remover and wiped with a tack rag. This is insurance against trash in the paint and to minimize any chance of fish eyes or paint not adhearing to the work surface. What kind of primer are you using? Epoxy, 2k urethane? Also make sure to read all the tech sheets and make sure all the products you are using are compatible with each other. With a high build primer there is no need to sand with a fine grit paper, 220 should more than enough, i used 180 or 220 before primer. Guide coat it. Block it flat with 220. Re-prime, guide coat, block it flat 320. Then it should be ready to get sealed and sprayed.
1993 Cobra (Bone Stock'ish)
1991 Coupe (Sold)