In general, to prepare for Berkeley, you should complete the a-g requirements (see: http://www.universityofcalifornia.edu/educators/counselors/adminfo/freshman/advising/admission/subjectr.html for more details), study and do well in your high school courses and standardized tests (SAT and/or ACT, and SAT II), take as many AP courses as you can handle (honors courses are not weighted for out-of-state applicants), participate in educational preparation programs available at your high school (see a list on my blog), and commit to one or two extracurricular activities in which you develop leadership skills (more is not better, quality is better than quantity).

Berkeley will weigh the following components of your application (in the order of importance): 1) your essay (new personal statement prompts will start for the Fall 2008 application cycle: http://www.universityofcalifornia.edu/admissions/undergrad_adm/apply/how_apply/personal_statement.html#fall08 ) about your background, personal quality, talent, accomplishment, contribution, aspiration and/or experience that highlight your motivation, dedication, and/or initiative to achieve, and any special circumstances like hardship; 2) your grades and any grade trends (improvements are better than just maintaining a high GPA); 3) your test scores, including SAT and/or ACT, SAT II; and 4) number of AP courses completed compared to the number of AP courses offered at your high school. Other factors are taken into consideration, but to a lesser extent.

Generally speaking, you need to average 630 in each section of the SAT. But with a GPA like that, you will need to go higher. Either that, or you’re going to need one heck of a sob story.

If I were you, I’d add a whole lot of volunteer work to your extracurriculars. Berkeley likes volunteers. Do some time at a public library, hospital or nursing home. Work with a disadvantaged population and have something profound to say about how the experience influenced you.

And not to be a total downer, but you are just a sophomore. You still have time to boost your GPA. Take lots of honors and AP classes. Do a summer college program after 11th grade. Berkeley does have open summer enrollment http://summer.berkeley.edu you can take classes and stay with your relatives for 8 weeks.

Otherwise, I’d say you need to aim for a 2200+. Possibly higher.

Define “good”. Because up in the Bay Area, you’ve got Berkeley and Stanford. Next tier down would be UC Davis (altho not exactly Bay Area). Below UC Davis and the pickings get real slim.