get the bikeways maps for santa clara country from here: http://www.vta.org/schedules/schedules_bymap.html
here's a similar thing for san mateo county, which you may have seen http://www.penbiped.net/project-nort...-downtown.html
SF to Mt View via caltrain is a pretty common commute around here -- the other direction also. google employees, of course, have their own private shuttles so they don't have to mingle with the hoi polloi. the light rail system that runs through santa clara county is efficient and relatively cheap but slower than biking unless you are going a long distance that lies directly along its route (say, santa theresa (s) or alum rock (e) to mt view).

The MUPs around here are not like those (i've read about) in the MD/DC area where they are primarily commute routes that get clogged with strollers on weekends. The primary MUPs here are primarily recreational paths that go nowhere useful and are clogged with strollers all the time. So yes, riding to and from work is pretty much going to be on the roads. The good news is, in addition to the "class 2" bike lanes you'll see on the bikeways maps, biking on the county expressways (labelled G-[1..8] on street maps) is legal, fast, and quite pleasant with the notable exception of Lawrence Expy.

if you're not dead-set on the SF urbanite life there are good bike-friendly downtown areas all down the peninsula, in mt view itself (though that would make for a short commute) santa clara and downtown san jose. I'd avoid sunnyvale, milpitas and south SJ unless you really like riding long distances in traffic. i live in campbell (light rail, farmers market on weekends, movie theatres within walking distance...) and commute 10 mi each way up to the santa clara/sunnyvale area. At least here in the south bay, the housing market is tanking which is good news if you're looking to buy but it means rents are tightening up.

anyway, i live and bike here and i'm an opinionated geek, so take it for what its worth -- your mileage will probably vary