I'll give you as much halp as possible. I wouldn't fill all six spots with prospects. David Price will be available since he just got bumped down, so look to take him late.
Here are a few players that look to have a big year but aren't well known:
Nelson Cruz OF - TEX Jarrod Saltamacchia C - TEX(Good back-up catcher to have, could have a big year) David Price P - TB Pat Burrell OF - TB (Not young or unknown, but you can get him very late in the draft) Jed Lowrie SS - BOS(Should start the year and could do well and keep the starting role) Mat Weiters C - BAL(He should be the starter before two months into the season, pick up before Salt if you can) Travis Snider OF - TOR(He should make it to the FA in your league, so I wouldn't draft him, but if Lind, Rios, or Wells go into a drought look for this kid to make an impact) Cameron Maybin OF - FLA( He will be drafted in the last two rounds, so if he is there, I would take him)
There are a few, I will add some more in a little bit, but here is some advice. Don't get carried away with prospects. If it's a one year league, 90% of the prospects picked up are worthless and most likely only one or two will actually make an impact on your team. You can get some great players in the late rounds. Have fun and don't think too much. Also, remember to go after the positions like 2B and SS in the early rounds because after a couple players, it is slim picking. Good luck
I am in an AL only keeper league and feel your pain on this question. It is tough. Beckham would be one to get, he might get playing time this year later on. He was just sent to the minors. Travis LaPorta, Trevor Cahill, Brett Anderson, Huff from Cleveland, and obviously David Price and Matt Wieters are two coveted rookies to get. Porcello, Poreda, Cunningham, Reid Brignac are other names to look for. Other than that off the top of my head there are lots of other names you look at. Use your magazines for names of players and then search for them on CBS sportsline or Rotoworld.com and they will give you updates on their status. Other rookies to make an impact and who will start the season in the majors are Travis Snider(going to start in Toronto), Adam Lind, Elvis Andrus, Chris Getz. That's all I can think of now but I will let you know if I come up with more later.