Apartment Hunting Between PA and SF (San Francisco, San Mateo: job, housing, price)

[Mercury529]

Thanks for any help you can give. I apologize for the long post, but it's a big move for me out from Cleveland.

I am moving to California for a job in Palo Alto, and I am looking to find housing. I have an opportunity to come into town Memorial Day weekend, so I have a few days to look around. My girlfriend will be looking to find an advertising job in San Francisco. I had a few questions.

Here's what I am looking for in housing in order of importance:
1) Safety
2) Character (prefer non pre-fab type housing)
3) Cleanness/Well-Maintained
4) Price

Here's what I am looking for in terms of community in order of importance:
1) Safety
2) Good downtown area (good restaurants, coffee shops, etc)
3) Easy to walk/bike around
4) Youthful community

And my questions:

1.) How bad would the commute be from Palo Alto to downtown San Francisco by car? How bad would the commute be from PA to downtown SF by Caltrain?

2.) What areas would be a good fit for the aspects I am looking in a community while still having a reasonable commute to PA and SF? What areas should I avoid in these neighborhoods. I have heard Redwood City and San Mateo might be a good fit.

3.) Can anyone recommend good housing to look into while I am in town? I have found some places through Craigslist but was hoping to find some more unique housing. A lot of the stuff on Craigslist seems to be the same complexes or lacks pictures to get a good idea about what the apartment is like.

Thanks for any help you can provide.