There is a great feature on minorleaguebaseball.com (milb.com), you can look up player's stats and find out how well they are doing at what level. Once you look them up, they give you the option to "bookmark" the players by clicking a flag on the left side. They put all the bookmarked players stats' on one page, making it very convenient to check.
It's really a great feature.
Zack Greinke...the next Greg Maddux. LOOK IT UP!
For what it's worth.