Many states, counties and cities provide low to moderate housing finance programs, down payment assistance programs, or programs tailored specifically for a first-time buyer.  You should always check in the area in which you are looking to buy. The CHDAP program is one currently being offered throughout California.
California Homebuyer's Down Payment Assistance Program (CHDAP)
CalHFA offers a subordinate loan program called CHDAP.  It is also described as a "silent second", meaning payments on this loan are deferred so you do not have to make a payment on this assistance until your home is sold, refinanced or paid in full. This helps to keep your monthly mortgage payment affordable. The CHDAP provides this deferred-payment junior loan – up to 3% of the purchase price, or appraised value, whichever is less, to be used for their down payment and/or closing costs.
Source: CALHFA http://www.calhfa.ca.gov/homebuyer/