Continue to check into scholarships. There are even books and computer software with scholarship lists. The summer before your senior year is a good time to visit your top three college choices. Your senior courses and grades do make a difference. See your counselor for dates.
Early fall is best.
Continue to visit colleges that you missed during the summer. Send your college applications in early. Provide all requested materials, e.g., recommendations, transcripts, test scores, and essays. If necessary, ask your counselor about a waiver for the application fee. You should be able to get them from the guidance office at your high school.