Occasionally a family will contact me. They say, "Our child has told ABC University he is coming there. We'd like for you to help us find scholarships now so we can afford it."
Two points:
First, no one is better qualified to find scholarship money than your student. The student who wants scholarship money bad enough can usually find some.
Second, an "after the horse is out of the barn" approach extremely limits the options available.
Ideally, we like to work with families of tenth and eleventh graders for the actual college selection process. For financial preparation, I'd say as soon as you know you're pregnant.