One on one therapy may be overkill, but don't rule out a coach or a group. Seriously - if this is something that you find you can't overcome from practice and a book, but want to, it makes sense to seek professional help in some form. For example, Los Altos has "The Shyness Clinic": http://www.shyness.com/shyness-clinic.html. I just found it in simple searching around - I'm not endorsing them in particular.
I'm a nerd too - and there's a ton of things that I couldn't just read and practice away. In fact, our intelligence often gets in the way of our progress - overthinking can do more harm than good on many social issues that plague us nerds. It's hard to stop overthinking by studying!
I've got a ton of friends who do group dance lessons to meet people and get out of the house.
General tips:
* Smile! It'll put others at ease and it'll put you at ease too.
* Leave when you're done - don't stay just because you feel bad you haven't spent n minutes there.
* Silence is OK - if someone talks to you, it's way better to take an extra 5 seconds (which will feel like an eternity!) and then start your reply than feeling like you need to respond the split second the other person finishes. It didn't feel natural at first, but when I listen to other people it happens all the time.
* Everyone loves to talk about themselves. Tell the person you're new to the area and ask them what their favorite drive, hike, day trip, restaurant, or hot new start up is. Ask them why. Ask them anything related. They'll think you're swell and you didn't have to have any deep searching to answer their questions!
What brought you out to the Bay Area anyway? And what are your interests?