A great place to meet other neighborhood babies and their parents is your local branch of the public library. Led by a children's librarian, parents and tykes sing songs, read stories, and do the hokey-pokey. Visit your local branch for more info. While their kids play with age-appropriate toys and romp on climbing structures, parents learn about and discuss topics like health and safety, sleep patterns, and toilet training. These are all free, no-credit classes.
Parents register at the site.
The S.F. Children's Council offers a resource and referral line for parents seeking licensed day-care providers.