If you use Yahoo!, just sign into your account, access your league, and go to the "My Team" tab. Under the "Status" column of your roster, you can click the time listed (for example, 1:15), and if the rosters for the game have been announced, they will be listed. Otherwise, you will just be taken to a preview article of the game. Lineups are usually posted within an hour of when a game is scheduled to start.
"When you don't feel good and you still get hits, that's when you know you are a bad man." -Manuel A. Ramirez