I would like to start a vegetable garden now (late summer). Which vegetables will do best with fall weather approaching? I am in southern California.
Also I would like to plant some herbs, which ones are perennial?
In southern California, you can pretty much grow the same things in the fall that you can in the spring. For example:
Anything in the crucifera family - cabbages, kales, turnips, collards, radishes (including any of the fall Asian types) bok choi, napa cabbage, kohlrabi, etc.
Onions - green onions, chives, garlic chives, leeks, shallots and garlic (for next summer harvest, and for greens over the winter)
Hardy salad greens: butterhead and buttercrunch lettuces, romaine lettuce, miner's lettuce (claytonia), corn salad, spinaches, chard, leafy herbs like dill, parsley, cutting celery and cilantro
I've even heard some folks grow potatoes over the winter in some places.
Everything I've listed above can stand a bit of light frost. If you expect more than that over the winter, invest in some spun-bonded row cover or create a frame of the appropriate height and give it a removeable cover of clear drop cloth plastic from the hardware store or if you want to invest in something that will last longer, some greenhouse plastic. Just be careful that you don't let the temps inside get too high, because while all of the plants mentioned above actually LIKE the cool weather, having them exposed to summer time temperatures during their over-the-winter growing season can cause them to bolt to seed and become tough and bitter - or even die. So only use solid covers (sheet plastics) when you absolutely need them and pull them back to allow the planting beds to cool when you do not.
Oh, and to clarify - start all of these just as soon as the weather permits - while all of the plants I've listed will live and even grow some over the winter, their growth is likely to be slow during midwinter. You want them to make good growth during the better part of the season so they will still have time to get large enough to give you a harvest during the slower growing part of the season.
I was in Ojai time ago and the weather is similar to the Canary Islands (with pronounced season, of course). This would be a list to get started:
The easy one (throughout the year):