Since I have to sell my Les Paul for financial reasons I was kind of thinking maybe a few months down the line I'd pick one up too.
Are you buying new? There really shouldn't be issues with a new one. Just make sure it works and there aren't any chips or dings.
For used, I go by the Dan Erlewine book
"How to Make Your Electric Guitar Play Great" . You can read the 1st 7 or 8 pages on Amazon, which is most of the "Evaluating a Guitar" section. Definitely worth a read.