An excellent book on California gun laws is: How to Own a Gun & Stay Out of Jail, California 2012 by John Machtinger, 192 pages (2007 edition which I have). It is published by www.gunlawpress.com but the 2012 edition appears to be sold out.
http://www.abebooks.com has the following editions listed for sale: 2008, 2007 and 2006 any of which will be adequate for your needs.
From the chapter entitled "Laws on Assault Weapons...:
1. Before bringing the [assault] weapon into California, get a special permit from the DOJ [California Department of Justice] to possess it in California ...
2. Deliver the [assault] weapon to a specially-licensed gun dealer in California according to federal law. Then apply for a special permit from the DOJ. If the permit is issued [you should do some research to see what the odds are of that happening] the dealer will return the gun to you.
Pending legislation classifying all semi-automatic center fire rifles with detachable magazines as assault weapons and thus banning the purchase and transfer of them is likely to become law in California. Living with 10 round capacity magazines is not going to ruin your life. Buying used hand guns that are not currently on the DOJ approved safety list must be done from a private party or be on consignment at a gun shop or show in California. The transaction must be done in person and picked up 10 to 30 days later in person. Or if the hand gun is on the BATF curio relic list it can be brought in from any state in the US to a local FFL. A Hand Gun Safety Certificate is required to receive a hand gun.
Bob Bonta, assemblyman from Oakland introduced legislation earlier this year to confiscate all assault weapons but withdrew it because of the impact it would have on the national debate on gun registration. Surely we will see this bill again.
The California Rifle and Pistol Association (www.crpa.org) is a good source of information on the status of pending (anti) gun legislation in Sacramento, as well as having a useful booklet summarizing California gun laws.
My suggestion is to buy the Machtinger book and comply with the laws.
Free advice from Menlo Park, CA