The link below lists both edible and poisonous natives. And reference several books
[1]Wild Edible Plants,Kirk, 1975, Naturegraph,,,,
[2]Edible Wild Plants,Medsger,1966,Macmillan Pub
/////
http://www.laspilitas.com/classes/herbs.htm#California Herbs in cooking -- California herbs in cooking
/////
http://artofmanliness.com/2010/10/06/surviving-in-the-wild-19-common-edible-plants/ -- Surviving in the Wild: 19 Common Edible Plants
/////
Hope these help ... Also might find ISHI - LAST OF HIS TRIBE useful ... as I recall there were lists of edible plants -- http://en.wikipedia.org/wiki/Ishi

Here is a link that might be useful: Edible Native Plants

I've read dozens and dozens of these books, and own a good percentage of the same, so it's no easy answer for me.

First of all, I'm not aware of anything out there that is specific to the SoCal Coast. Most are more general or have a regional bias without making that clear in the title.

My all-around favorite is without a doubt: Edible Wild Plants: A North American Field Guide to Over 200 Natural Foods, by Thomas Elias, Peter A. Dykeman. It packs loads of information into a manageable sized book, including harvesting methods, nutritional stats, and preparation instructions. It is the only user friendly edibles guide that can really be used anywhere on the continent.

A Taste of Nature by Kahanah Farnsworth is a nice little book for the beginning forager with an obvious SoCal bent, and some useful recipes. Edible and Useful Plants of Texas and The Southwest by Delena Tull is another great resource, although it's too big to take in the field with you.

I could not give any recommendations under this topic without mentioning Euell Gibbons. His books remain the most accessible, realistic, and interesting to date. His Stalking the Wild Asparagus is a general guide with a Northeast focus, but includes all of the major edibles that are common anywhere.

Finally -- I apologize for the length of this, but you've hit on a passion of mine -- you might want to familiarize yourself with the host of temperate and sub-tropical zone weeds and cultivated edibles. When I go to Southern California, my best finds are not native wild plants, but rather naturalized non-natives. In fact I would say that the native flora of Southern, especially coastal, California is one of the poorest for fleshy fruits especially, and edibles in general. BUT, add to this the multitude of introduced plants that produce numerous luscious things and you have a region that is hard to beat for the forager.

So I hope you find some books that suit you, and don't be afraid to check out that vacant lot loaded with fruiting olive trees, pineapple guavas, fruiting palms, or the dandelions in your yard, and the weedy mallow coming up in the park.