determine if you are eligible for respite care through the regional center (the state may pay for babysitting), and apply for it.
find out if there are is a county level book and media "library" for special education (Orange county has the "comfort connection", for example).
attend as many support group meetings and training as you can
if your child is between 2 and 3, find out if your county has an early learning program sponsored by the regional center (e.g., Orange County has the IntraAgency Assessment Center early learning programs).
if your child is between 3 and 5, obtain an IEP from your school district, and get your child enrolled in special ed preschool.