Get Steve Solomon's book on winter gardening in the Maritime Northwest. Northern California is the southern most area covered in the book.
Peas of course.
If you can rig up a cover of some sort to keep excess wet off of the plants you can do mixed greens and endive. I have a collection of windows in frames that I put over my greens with cinder blocks. They really need protection from the rain then they do from the elements.
Overwinter broccoli and cauliflower should do fine. It is late to put them in here.
If you have brussels sprouts growing already, trim them up and let them grow. If you get frost they will get as sweet as candy.