I live in San Mateo and have taken my 2 yorkies to a few different places. I'd recommend either Bow Wow Meow in San Carlos or Super Pups in San Mateo. Of the two places, I prefer Super Pups- it's a husband and wife who run the shop and they get them done is a timely manner. (I've dropped them off btw 8-8:30 am and pick them up btw 11-12). The only thing i'd recommend is that you specify you want your puppy to have a top knot, even if they dont wear them, b/c they tend to cut the top of the head kinda short & I just like their hair to be a bit longer.
Bow Wow is also good, but i feel that their cuts grow out really quickly and get choppy as the hair gets longer, but I know TONS of people who take thier yorkies there.
I've also been to a place in Burlingame called Pawsitively Groomed (sp??)-nothing special and i have not taken either back.
Good luck!!