The California Department of Developmental Services has a comprehensive web site that can answer many of your questions such as what is a developmental disability? or who is eligible for services?
You may know that many of the developmental centers (institutions) are in the process of being shut down – you will find progress reports on the DDS web site. There are new federal rules about “Home and Community Based” services – the DDS site has that information along with details on the Early Start and the Self Determination Programs.
Perhaps the most helpful thing is access to a copy of the Lanterman Act – the law that guarantees state funding for services for people with developmental disabilities and their families. Also helpful is the “Consumer Guide” to the Lanterman Act – which boils down all the legal stuff into an easy-to-read booklet.