Please, enjoy these Links.Baseball Reference - All you'll ever want to know about every player. Ever.
Baseballcardpedia - An invaluable, community-edit baseball card information site with checklists for most sets.
COMC - An easy and addicting way to buy/sell with images of every card available.
Dave & Adam's Card World - A solid marketplaces for packs and boxes from yesterday and today, not unlike the music on that radio station your Mom listens to.
eBay - You know what this is. Don't get gouged.
Franchise Ball - A free real-time baseball simulation game.
Freedom Cardboard Griffey Collector's Thread - Get your drool towel ready.
Just Commons - Like COMC, but no pictures. Lots of great finds to be had here.
Sportlots - A different way of buying large quantities of cards direct from buyers.
Wax Pack Gods - A pretty comprehensive list of hobby-related websites (including this very blog!).