You need to buy FSS for the states that you plan to recruit from, or use scouting trips, but FSS is a lot cheaper.
Once the players are on your roster, their potentials are color coded..
Red = low = 0-5 pts of growth remain
Black = ave = 6-19 points
Blue = high = 20 or more points of growth remain.
The key at D3 is to find guys that are 400-450 now, but can grow into 650-700 level players by the time they are upperclassmen.