Some might question my ethics here, but if someone was really prepared then the question would have never been asked in the first place. Read injury reports religiously. Look for conditions that could hinder a player for the remainder of the season. The NFL releases their injury report Wednesday and updates it Friday. Make sure you read it each week.
Information is key and interpretation of that information is power.
Stl 30, SF 22. This can be helpful to determine when a team and it's players may have a big week. Most fantasy football websites now possess good depth charts. No, I am not suggesting you buy a crystal ball or call Latoya Jackson for psychic help. But looking at mock drafts, average lists and consolidated expert rankings will give you a good feel to where players might get drafted.