GGB info. Going north, there is no tolls. You'll go through the tollgate but you don't stop. Going south there is a toll. $6 per bike.
There is a parking lot on the south side of the GGB. It has no view. Don't plan on stopping there.
On the North Side of the bridge (accessible only when travelling North) there is a parking lot that lets you see the whole bridge and all of SF. Sometimes there is a line to get in; just depends. Perfect shutterbug opportunity. Recommended stop.
From there Petaluma is just a casual drive north of about 35 minutes. The scenery after San Rafael is boring but lots and lots of CHP patrol the area so speed limit should be obeyed.
IF you want to take a slight break, Highway 37 at Novato hooks East and 15 minutes away is Infineon (Sears Point) Raceway. There is an AFM (American Federation of Motorcyclists) event that weekend there. If you want to go I can get you in easy enough.
Once in Petaluma use this address for where to get fuel.
Chevron, 1002 Lakeville Street, Petaluma, CA
It's the southernmost good gas station in Petaluma.
This oughta be fun! I'll ride back south with you guys to 37, then I hook east to head home.