Bicycle class, my friend told me, we went.

The most important thing that we learned:

Bicyclists don’t have to ride in bike lanes, or even stay to the right.
In general, California law calls on cyclists to stay to the right and use bike lanes when available, but cyclists can ride elsewhere if they find it safer to do so.
Specifically cyclists can ride in the left part of a lane to make a left turn or on the left side of a multi-lane, one-way street.
They can move into the middle of the lane to avoid obstacles — including when cars are parked along the curb, because motorists often open car doors and can knock cyclists down.
Bicyclists also can move away from the right side of the lane near intersections where motorists might want to make right turns in front of them.--- If I knew it, I could have avoided the situation I wrote about yesterday.

And checking behind often is necessary:
     before the hand sign to turn, and before actual turning.
And make eye contact to the driver as possible --- For these I need more practice.

The county bicycle coalition certified teachers gave us free 4 hours class in the room and outside to explain the situations.  

That was very nice we both thought.  We spent the valuable education time.  --- In addition we learned that the city of Sonoma changed the law recently so bicyclists are not allowed to ride on the sidewalk anymore.

All the attendees got free gifts, it's very nice.