Super easy, depending on where you start (with the bridge down to one lane be careful going over to Marin) say San Francisco. Just ride straight over to Sausalito and keep going north to Fairfax, lots of cyclists and not easy to get lost. Take a left in Fairfax on the Bolinas Fairfax Road, and start climbing, you take a break at Alpine Dam then climb out to the "Seven Sisters" which ends at Mt Tam you have an option of turning left again and climbing up to the top of Tam or bombing down back to San Francisco. It is a great ride. Do it now before it gets too hot!
PS we are doing that ride this weekend leaving from Mike's Bikes in Sausalito on Sat the 18th at 8:30 you are more than welcome.