In 2008, search-engine marketer and Chicago Cubs diehard Tim Dierkes quit his day job to focus on his blog, MLB Trade Rumors. Dierkes and nine other writers now contribute, sharing scuttlebutt about trades and free-agent signings for all 30 Major League Baseball teams. It's a rich source of relevant information on its chosen subject, and it's admirably fat-free: almost everything is in the form of quick-hit bullet-pointed items. With tools like the Transaction Tracker, which lets you search for deals by player, team and contract value, this site can make anyone feel like a major-league insider.