We rented bikes down by Fisherman's Wharf. From there, you ride your bike - with lots of breaks for pictures/fun - along the shore to the Golden Gate Bridge, over the bridge on the pedestrian/bike sidewalk, and then it's all downhill to the town of Sausalito to get some lunch. (It's pretty much downhill from the middle of the bridge to the end of the ride) From Sausalito, take the ferry with your bike (and about 100 other bikes, really) back to Fisherman's Wharf to drop off the bikes. The ferry ticket back was included in our bike rental.