biking over the GGB is something tourists do every.single.day here in sf [weather pending] and i haven't done it since i moved here back in 2010. if you can avoid some of the madness that is inevitable with something like this, it's really quite fun. a few tips to surviving: 

1. stop for sugar and coffee before crossing the bridge, because hills are coming! dynamo donuts in the marina is one of my favs
2. beware of crazy tourists – there are so many people snapping photos with selfie sticks and not riding their bikes properly that it's legit dangerous 
3. skip the first strip in sausalito –  it is super cute and quaint, but the great restaurants are on the other side [in my opinion]. some of my favorites are: le garage, fish and bar bocce. 
4. take the ferry home – biking up the never ending hill you just flew down to get into sausalito will probably ruin your buzz 
5. if you don't want to go to sausalito – some other fun stops are cavallo point or rodeo beach