EdSource is a California-based organization with off-putting school reform policies, but it sometimes produces useful materials.
Their series of Student/Parent Guides: Beyond High School is an example of these good resources.
They are short and accessible guides — focusing on California — available in English and in Spanish on these topics:
A Guide to California’s Community Colleges
A Guide to CSU Admissions Policies
A Guide to UC’s New Admissions Policies
No high school diploma? You’ve got options!