As a new player, don't be afraid to rate C, 1B, and DH with All-Star quality bats, or RPs with very high control and splits and at least one great pitch right alongside players at other positions with much higher OVRs. Better be a freaking great bat to push a DH that high, though.
Don't be afraid to drop high OVR players whose ratings don't measure up down the list. An example would be the high Dur/Sta SP with good stuff and projected control in the 20's. He might project to 75 OVR, but he's not a ML prospect. If your gut tells you he can't play, he probably can't.
Rank DHs in about the same spot regardless of whether you play in the AL or NL. If it's really close between two players and you're an NL team, then maybe rank the DH lower. But don't pass a DH with a 1.000 OPS bat for a LF with a .750 OPS bat just because you're an NL team. You can always trade them later.
One additional tip for finding backup player prospects is to sort by power, and then resort by power so the bottom of the list comes up. Sometimes a guy with near "0" power can have a low OVR but still play at the ML level with okay splits/BE, especially if they can play 2B, 3B, or CF.
When you're done with the defensive specialists, DHs, and varius backups, I would also throw in anyone with speed over 90. Even if all they do is come up in a couple of years as a designated pinch runner after roster expansion, it's still a skill that could see them to the big leagues.
I also take a few minutes to line up a few innings-eating SPs (high dur/sta, with split/control projections of better than 30), because they make running your low minors much, much easier. Additionally, I like to make sure I draft at least 13 P, 2 C, and 2 SS. Having depth at these 3 spots will allow you to keep minor leaguers fresh without spending much time on them all season.
Finally, altough vsR is the far more important offensive split, don't forget to sort by vsL projections and look for platoon players. Sometimes a guy with a projected offensive line of 50-80-75-15-50 can be had even in the 4th round because the terrible vsR gets him sent to the bottom of people's lists. But this guy could possibly platoon for someone at the ML level under a specific set of circumstances.