That would depend on a few criteria. It depends on how long you have lived on the property. If you have lived in the house for 2 of the past 5 years, there is a capital gains exemption. You will not have to pay capital gains up to 250k if single or 500k if married. If it is an investment property, you can deferred the capital gains tax by doing a 1031 exchange. Good luck and hope that helps.
Of course, if it does not qualify as your personal residence through this method or if you are lucky enough to anticipate more than $500,000 in profit from this sale you should contact your CPA for advice.
A lot of the answers will depend on how many years the home that you own have been rented for. To take advantage of capital gains exclusion, you need to have lived (owner occupied your home) 2 of the last 5 years. The order of the years is not important.
If you lived in your home 24 months out of the last five years, it can still be considered your primary residence in California. I think they even relaxed the law a few years ago, and those 24 months don't have to be consecutive. As far as taxes, you should really talk to a tax consultant or an accountant to get the correct answers. You may also want to talk to an escrow officer to make sure what I told you is correct. I admit to being a little fuzzy on the details.