For a California resident, most of the CSUs are typically in reach of B students (but some are competitive, though there is also a local area preference). For cost and financial aid estimates, see http://www.csumentor.edu/finaid/pais/ . Non-impacted majors at non-impacted campuses will admit a student who has completed the specified a-g courses in high school and earned a 3.0 GPA in them. However, many campuses and majors are impacted and require higher GPA and test scores; see http://www.calstate.edu/sas/impactioninfo.shtml .
Some of the less selective UCs (Merced, Riverside, maybe Santa Cruz) may be in reach also. Their net price calculators can be found on their web sites.
California also has a well developed transfer pathway from the community colleges to the UCs and CSUs, where students take their frosh/soph courses at the community colleges and then transfer to the UCs and CSUs as juniors. This is often taken as a lower cost option, or an option for students who want to try to transfer to a more selective campus than the ones that they could be admitted to as frosh.
The student should be aware that the 11th grade PSAT can qualify for National Merit scholarships (see http://nmfscholarships.yolasite.com/ ). S/he should also consider taking both the SAT and ACT in the later part of 11th grade, since having the scores by summer can allow a better estimate of what colleges are in reach, and allow for a retry of the initially higher one if desired.
The a-g high school course requirements for UC and CSU are described at http://admission.universityofcalifornia.edu/counselors/files/csu-uc-a-g-comparison-matrix.pdf . In some cases, high enough SAT subject or AP scores can also fulfill part or all of the requirements in a category.