In California--for the time being--things are different than in the rest of the U.S. On January 1, 2016, California will switch to the national ASWB exam that everyone else now takes. They'll throw in a California-specific law and ethics exam just to keep left coasters on their toes.
Right now (pre-2016), there are two exams standing between you and an LCSW in California: the standard written exam (which looks just like the ASWB clinical exam, but includes some questions about state law particulars). It's 200 questions long. You have four hours to complete it. The second test is the clinical vignette exam. The stems of exam items look the same as on the first exam (the "stem" is the question part). The answers though are much different. They include four sets of answers per A, B, C, D. Multiple exam items refer to same vignette. To work your way through these in the time allotted takes focus and some kind of scoring system--different exam companies suggest different approaches (e.g., rating choices 0-2; check-minus through check-plus). Find what works for you and stick to it.
Both exams are administered by the California Board of Behavioral Sciences. Poke around on the site for lots and lots of information, including this sobering stat: Last year's standard written exam was passed by only 50% of applicants. Yikes! Other years have been better--and worse. Good preparation is apparently not optional.
What's good preparation look like? Know what you're heading into. Read up on the BBS site. Take a look at the pdfs linked on NASW-CA's new page, Obtaining a California LCSW--Made Easy! And, of course, get some practice in. Practice tests, like those offered by SWTP, not only drill you on content, they get you familiar with what it feels like to sit still for four hours and think like a textbook social worker.
Congratulations in advance, California LCSWs. It's only a matter of (effort and) time!