Late summer marks the start of Apple season, and plenty of the tasty and popular fruits can be found in the North Bay, especially in the area around Sebastopol in western Sonoma County. Sebastopol is the de facto apple capital of the Bay Area, and it's justifiably famous for its Gravenstein apples, a variety that you won't find grown commerically anywhere else. While it's fun to eat and cook with apples, it's even more fun (and educational) to head out into an orchard and pick them yourselves!
If you're not lucky enough to have an apple tree growing in your backyard, then head up to one of the local apple farms that offers a u-pick experience. It's a fun family outing, and prices and quality are usually bettter than you'll find in the supermarket. There's nothing quite like an afternoon on the farm, too.