Sit through a class.
Stay a night... keep in mind that every college on earth is fun on a Friday night, perhaps visits during the week wouldn't hurt.
Talk to athletes, non athletes, ex athletes.
Talk to professors.
Talk to alums.
Eat the cafeteria food.
See some dorm rooms.
Visit during warm and cold months.
Sit in the dugout during practice.
Watch a practice without announcing you are coming.
Watch some games or scrimmages.
Wow! You said you were shooting from the hip, so okay. But even from the hip, if this is due diligence, I'd bet 99% of kids in college are negligent. I'm shooting from experience. Realistically:
Do research online
Talk to students
Talk to guidance counselors
Visit the grounds
Study the athletic program inside and out if you're planning to be an athlete
Make a decision