There are several places to launch a trailerable boat. I suggest that you go in around Rio Vista on the Sacramento or somewhere around the San Joaquin & Mokelumne.
You may be surprised about the amount of wind that is generated over in the Delta. It is rated as one of the "BEST" wind surfing spots in the US, so be prepared to reef early & reef often.
The rivers are large enough for large ocean going vessels (container ships, freighters etc). If you venture south/west you can reach the San Pablo & San Francisco bays. There is supposed to be over 1,000 miles of navigable waterways in the delta.
There are also an untold number of places to anchor over-night (or for the rest of your life) if you want.
During the fall & winter there is very little wind. During the spring & summer we see a lot of 15-30 kts days & nights. There are lots of marinas for gas & minor groceries, but it is best to be well stocked if possible.
http://www.deltaboating.com/about.htm
Just search on California Delta and you will find a wealth of info. I have had a boat down in this area for over 30 years and can't think of a place that I would rather be most of the time.