totally forgot the rotoworld twitter.http://twitter.com/rotoworld_bb
forgot this one too from razzballhttp://twitter.com/razzball
theres also fangraphshttp://twitter.com/fangraphs
i havnt checked really, but i imagine most if not all the fantasy baseball websites have a twitter.
if you want to go ever further, there are alot of actual players that have twitter. you could follow them and get first hand information. you can also send them them tweets and talk to them. im not following any specific players, but maybe some will actually reply back to you.