Start in San Francisco, the centerpiece of Nothern California, well-known for its steep rolling hills, Victorian architecture, summer fog, liberal community, scenic beauty, and great ethnic and cultural persity. It is no wonder many visitors have left their heart in San Francisco. I recommend staying here 2 to 3 days at least.
What to do:
Within the city limit, don't miss the iconic Golden Gate Bridge. There are many ways to admire it including riding a bike on it but the best spot definitely is Marin Headlands located on the Northwest side of the bridge (not to be confused with the Vista Point on the Nothern side). You’ll get an amazing view with the city skyline in the background, best with the afternoon light. Check out the Fisherman’s Wharf and its sea lions on Pier 39. Fisherman’s Wharf is a broad area by the waterfront where you can wander and get you share of touristy shops. One of the best ice-cream spot is there in the Girhadelli Square. From there, you can embark a boat toward the world’s most legendary prison Alcatraz (official website), once host to America’s most notorious criminals such as Al Capone. Note that you usually need to reserve your combined boat/entrance ticket to Alcatraz several days or weeks in advance. Visit China Town that has the largest Chinese community outside Asia and become immersed in a microcosmic Asian world, filled with herbal shops, temples, pagoda roofs and dragon parades. China Town is best visited by walking on Grant Avenue. San Francisco has a rich collection of top restaurants, whether it be in a chilled-out bar, at a gig or on a pulsating dance floor.
Other places in San Francisco to strongly consider in no particular order: the renowned gay district Castro featuring a giant rainbow flag and many shops and restaurants, the Coit tower from which you'll have an impressive view of the city, the beautiful Palace of Fine Arts reminiscent of Roman and Greek architecture, Alamo Square Park home to the Pink Ladies (a row of Victorian houses with the city skyline in the background), the crooked, curvy Lombard Street on Russian hill, the free Cable Car museum on Nob Hill, the Ferry Building market near the Financial district (especially on Sunday morning when it is surrounded by a huge farmer’s market), Union Square the center of shopping and theater in the city, the Golden Gate Park where you’ll find the acclaimed M.H. de Young Memorial Museum and California Academy of Sciences as well as the Japanese Tea Garden, and the California Palace of the Legion of Honor in Lincoln Park.
Just outside San Francisco, the Napa and Sonoma valleys are famous for their wine, and you should definitely go check out the giant redwood trees at Muir Woods just North of the Golden Gate bridge.
Start your drive South on the beautiful Highway 1 to Monterey. It will take you 2h30 for this leg (and 30 minutes faster if you start by taking the I-280 road). As explained in the conclusion, if you have extra time, check out Santa Cruz that is on your way.
Find more info: San Francisco on Wikivoyage