College planning for high school students involves much more than filling out forms, taking standardized tests, and asking teachers for recommendation letters. The process also requires self-reflection and spending time looking at public and private colleges, online learning, and other forms of higher education that you may not have considered previously. 

9th to 12th grade: https://admission.universityofcalifornia.edu/counselors/files/My_Academic_Planner-EAOP.pdf