Originally posted by: empire
I have a decent sized collection. Brickset is the best online resource, and Bricklink will give you an idea about value. Box condition usually doesn't matter as much as piece condition. Collectors want sets to show as little wear as possible. The most popular stuff for collectors is mid 80s to mid 90s Pirates, Castle, and Space sets.
Also for god sakes, its Lego, not Legos.
I keep telling my sister she's sitting on a mint. She snagged every Pirates and Castle set she could find when we were growing up and when she was in college. She still has them all in their respective boxes.