1) Buy or borrow a copy of Pam Peirce's book GOLDEN GATE GARDENING.
2) Think small.
3) Think fall.
GOLDEN GATE GARDENING by Pam Peirce is subtitled: A Complete Guide to Year-Round Food Gardening in the San Francisco Bay Area and Coastal California. It's all there and is based on her real experience maintaining a garden on the western side of San Francisco, in The Avenues, not the Sun Belt of the Mission District. She knows all about fog, wind, salt spray, and cold spring and summer days.
Since most of us - including me - behave as if we are still gardening in Ohio and since most seed packets carry instructions that assume we are gardening in Ohio, then we have a skewed notion of what to plant and when to plant it in this lovely Mediterranean climate that we have here. Vegetable and herb gardening is not just a springtime activity. It is a year round activity and one that can provide you with unimaginable amounts of fresh produce. But sadly, probably not those big, luscious Brandywine tomatoes that you love.
So read her book and revise your thinking about what to plant and when to plant it. There is a great planting calendar in Chapter 3 - What You Can Grow.
By "think small" I mean think of varieties of vegetables that are smaller in size than their larger brethren. For example, you probably won't have enough sun to provide the energy that a Brandywine or Big Rainbow needs to make that big tomato. But you probably do have enough sun - or light - to power the tomato plant that sets smaller tomatoes such as Stupice, Pink Ping Pong or any of the sweet and productive cherry tomatoes. Melons can be very disappointing to the home gardener in cooler climates. But if you use a solar mulch, put a drip system under the mulch (melons need a lot of water) and select varieties that do well in cooler climates (Hale's Best cantaloupe and Crimson Sweet watermelon) you stand a good chance of harvesting sweet, albeit small, melons in late summer.
By "think fall" I mean think of the plants that grow well in early spring and late summer. The kinds of plants that people in sunnier climates plant in fall will do well for you all summer. You can grow all the cool weather lettuces, for example, and your kales, chards, collards and mustards will provide terrific salads for you while other are limited to two kinds of garden lettuce. Basil, peppers, eggplant and other heat loving plants can be tricked by planting in raised beds, planting close to a south facing wall, using plastic mulch to hold heat in the soil, and barriers to keep the foggy wind off the plants. Large containers make good homes for these plants, too, and have the added advantage of being movable if they are on wheels. Container plants need more water, especially in windy environments, but if you clump the containers together, use thick black plastic pots, and - dare I say it? - use a controlled drip system, you can be more economical in your water use. You may not have warm enough soil to plant green beans, but you can grow and harvest peas throughout the summer.
Three final points:
First - Don't complain about your fog and wind. You live in one of the most glorious locations on earth and a little fog is a small price to pay.
Second - temperatures increase dramatically for every mile you travel inland. So make friends with one of those market gardeners who come to your farmers' market from Hollister or Salinas - they can bring all the big luscious vegetables you can't grow and they are only a few miles away.
Last, you have traded a cool climate for a very long growing season. In Ohio, they have from late May to early September to fill their larders. Here, we start in February and keep our gardens going through December (if you don't count all those garlic plants, walla walla onions, beets, fava beans, cabbages, chards, sweet onions, and lettuces that are overwintering!) So enjoy your cool climate and remember, strawberries HATE 90 degree temperatures.