There's not a short answer because it varies quiet a bit depending on what you have, what your own skills and temperament are like, what sorts of time line you have and so on.
There are 3 basic paths for resale:
1) Direct retail. This means eBay, Craigslist, Friends, Friends of Friends, neighbors, coworkers, websites full of ads, etc. The unifying thing here is that you are doing all the work to put the deal together. It's well regarded around here because this is usually the top money. It's also the top risk, the most amount of work, the most expenses up front, and it tends to be dependent on your own selling skills. Some people are a lot better at selling things then others and that's not a gemological property.
2) Direct sale to a dealers. There are tons of dealers who buy things and nearly everything is saleable. Cash, up front. It's a matter of the price. This ranges from jewelry stores to pawnshops. Bids are free and you can usually just visit one or a few, collect bids, take your money, and it's their problem now. The upside is that it's fast, easy, requires little skill and zero investment on your part. The downside is that it often leaves money on the table. The dealer is doing this for money after all.
3) Consignment. The difference between this and direct dealer sale fundamentally has to do with when you get paid. Basically, you don't get paid until they do. This includes auction houses, jewelry stores, and various forms of brokers. Normally it pays better than direct sales, but you have to care if your consignee is doing their job. Are they still in business? Are they paying their bills? Are they displaying things in a reasonable way? It may sell quickly, it may not ever sell. That is to say – it's still your problem.
California is a big place but limiting your approach to something that doesn't involve shipping, and the related risks, actually makes the decisions easier. Visit a local appraiser and figure out what you have. There's a list at the top of the page under the 'resources' tab. Visit some local buyers, like the local jewelers and pawnshops and ask them what they'll pay. While you're there, ask if they do consignment deals and, if so, what are the details of the program. Talk to your relatives/neighbors/coworkers and see if anyone is interested.