Meredith,
We attend FCCB (First Congregational Church of Berkeley) and love it. FCCB is part of the United Church of Christ. It is the oldest Church in Berkeley and has a long history of being a forward thinking, welcoming and family oriented church.
They have extensive Sunday School and Child care with certified caregivers for children under three during the service if your little one is not up to sitting quietly.
The music if fantastic as well.
You can get all the infor for FCCB at www.FCCB.org. You can also check out the UCC website for other churches that might be closer to where you live. The website for the UCC is www.ucc.org.
I hope this is helpful and good luck with your search.