danielfjohnson.com — My professional site. Visit the portfolio for some non-blog archives.
Baseball Reference — Easy-to-use source for both traditional and sabermetric stats.
FanGraphs — Sometimes pretty heavily sabermetric-slanted blogs, but hey, the graphs are cool.
MLB Blogs — I guess you’d call these “MLB-sanctioned” blogs.
MLB Trade Rumors — This site is devoted to trades and other transactions in baseball. It’s useful for the speculating type.