The best way to get answers to basic questions like this is to do a search onthe board. Most basic questions have been answered in depth many times.
Here are few hits for you to review;
http://hotrodders.com/showthread.php...=sanding+paint
http://www.hotrodders.com/t690.html
http://www.hotrodders.com/t123.html
http://hotrodders.com/showthread.php...light=3M+paint