My two pennies worth of suggestions:
-Help them be responsible for their learning. Teachers are responsible to teach in High school. College professors are responsible to be available for students who want to learn, but greater responsibility lies on the student than before.
-Show them how to identify resources available to them and how to make the most of those materials.
-Help them identify how they learn best. What study techniques are most effective for them? What techniques aren't as effective? Could the use of these techniques be improved? (Teach them how to study efficiently. There is no perfect one-size fits all equation for this. It has to be personally tailored.)
-Help them become good writers. A correct answer that can't be communicated appropriately won't get points, whether in the college classroom, work place or life!
-Encourage them to reach for the moon and work hard. Make sure they know of all the opportunities and options available to them in college.