FantasyFootballCalculator's tool predicts draft scenarios based on average draft position data, compiled from over a thousand mock drafts. Enter your league format and size, and it'll give you the statistical odds of each player being available at any given draft pick.
For example, the picture below shows who might be available at the fifth pick of the first round. If there's a low probability player available at one of your picks, you want to scoop him up fast (after you make sure he didn't just get hurt). It's also a good idea to look ahead to see what players might still be there for your next pick — maybe a QB can wait.