I'm your neighbor in San Ramon.
I can suggest quite a few rides that start in our neck of the woods. As prathmann suggests, the Valleyspokesmen have a pretty nice repository of que sheets. Also, the local bike shops (California Peddler, Pegasus, Dublin Cyclery) have organized rides all the time - both road and mtb.
Tell me what you're looking for in general, and I'll be happy to make suggestions. Mileage, climbing, loops vs out-and-back, that sort of stuff. PM me, and we can chat over the phone if you like.
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"Love is not the dying moan of a distant violin, it’s the triumphant twang of a bedspring."
S. J. Perelman