I've always liked George Washington, and he has some pretty good things to say . . .

"Associate with men of good quality if you esteem your own reputation; for it is better to be alone than in bad company."
-George Washington

"To err is natural; to rectify error is glory."
-George Wahsington

I found these quotes on famousquotes.com
It is an awesome websites for quotes because it is really easy to navigate to, and has a lot of famous quotes.