Yes, gillespie is right - if there was a redshirt last season he will still be a freshman so you could only sign five freshman then.
I agree you should focus on recruit quality rather than filling spots, too.
Focus on finding four or five solid players with good potential to build around. If you can get some other guys who are solid or fit specific roles, do that too.
If you can get some JUCO guys, not only will they vary your classes, but since they tend to have higher ratings they can help talent wise for the first season or two and make you at least a little better that way.
The important thing is to get players who fit with the team you're trying to create. Don't just grab any player who seems to have talent.