Highly recommend a Segway Tour
We did it when my son was 14 (minimum age allowed there) and had a blast - probably the highlight of the trip! Wish we'd had time to do the advanced tour, that one takes you down Lombard Street
. There are a couple companies that do these, and they originate in the Fisherman's Wharf area. Think we used the Electric Tour Company or something like that.
We stayed in the Fisherman's Wharf area, knowing full well we were in the thick of the tourist area. But it was a good location for us, easy to get public transportation (didn't rent a car until the end when we went north for a few days to Muir Woods and Sonoma), lots of food options, and generally things going on well into the evening. But it is touristy and that may not be the atmosphere you're after. We good a good deal at a Marriott that had just been renovated, right behind In and Out Burger and thought it was a good location.
CityPass was a good deal as we had already planned on going to most of the places included. It was also nice to have unlimited bus/trolley transportation and the requisite cable car ride was included. Lines for the cable cars were LONG, if possible I'd do that first thing in the morning and not on a weekend.
Something I haven't seen mentioned is the Saturday a.m. Farmer's Market at the Ferry Building. Oh my - if only I could shop there every week
The variety and quality was amazing, from vegetables, to cheese, meat, baked goods, the list goes on..... And the Ferry Building is worth seeing by itself, great architecture.
Alcatraz is a must see, make sure you have warm clothes with you. Very chilly out on the water. In fact, we found SF generally cool when we were there, not a lot of opportunity for shorts in the summer for us.