buying a used car

anyone know of any good guides to buying a used classic car? like what to look for, etc (esp for a 70-72 chevelle)?

thanks

Lift the mat in the trunk and look at the sheet metal for rust. The same for the carpet in the front. Crawl underneath and look at the frame for excessive rust. Do a carfax check if possible. If it seems like to good a deal, it probably is.