National Education Technical Assistance Center houses links to IDEA Part C (birth to 3 years) and Part B (3+ years) services State-by-State, and county-by-county.
Because intake in IDEA programs may be slow, if children are < 6 years and low-income, it is also wise to suggest referrals to local Early Head Start and Head Start programs. These services can obtain help from IDEA (e.g., speech-language pathology, physical and occupational therapy).
Find mental health services.
The Administration for Children & Families can help you find social services for help with domestic violence, child abuse and neglect, adoption, state, and local services, etc.