The best school district is Sunset. The only places I would actively avoid are along Railroad/Chestnut between L and P, just because a lot of homeless frequent that area. There are a lot of really nice areas though. Last I looked, it was hard to touch anything for under $500K, but prices have come down a lot in the last 3 years, so I'm sure you could find that pretty easily.
Re: Livermore Mommies
NorCalMOMS bio* NorCalBOTB* babywearingBIO
Harmony Doula
NorCalMOMS bio* NorCalBOTB* babywearingBIO
Harmony Doula
If you don't mind being off Vasco, I loved the area of Vasco/Scenic/Herman.
We ended up near Costco and love it also.
Stay away from right near O and Linden.