I was going to suggest China Camp also. You need singletrack skills though as it can be narrow in the middle stretch. California is a lot of long steep climbs on fire roads.
The Railroad Grade should be good training ground though. It is, um, the easiest climb on Mt. Tam. Just settle in and find the zen of climbing. V's photo above was a big 24 mile loop of Tam from Lake Lagunitas (Sarah, did you see the lilies! Inside joke, sorry.) with 3,560 ft of climbing. You'll be ready for it in no time if you keeping riding the RR Grade and add in the summit.
Then head over to Briones of you want training rides averaging 183 ft/mile.
If you're ever up in the Gold Country, try the Pioneer Trail (outside Nevada City) and the Olmstead Loop (in Cool) for more mellow singletrack.
Frends know gud humors when dey is hear it. ~ Da Crockydiles of ZZE.