Don't draft for position in these drafts. Minor leaguers are good chips to trade, and they don't always pan out to what people think they can do.
I would go with best available for each pick, just make sure after 12 or so picks it's pretty even between hitters and pitchers.
BA Top 100
as a guide. Check out this link
, it has the top 100 prospects of past years. Go through a couple and realize that, just because some is ranked in the top 10 doesn't mean they are going to be good. Don't put too much time into looking at who the better pick is, Maybin or Bruce(who are ranked 6 and 14), because it's like arguing between Blalock and Burroughs in 2002 (ranked 3 and 4). Burroughs looked to be great, but never lived up to expectation.
Colby Rasmus is a good pick at 27, though he probably could go earlier.