ASHA is the organization through which speech-language pathologists become nationally certified. Their website offers user-friendly information regarding speech and language development and disorders as well as suggestions for parents.
This website offers great information about autism in general and provides several links to resources for individuals and families of autism.
Another resource that highlights critical milestones for communication development for ages six months to eight years.
This website gives articulation tips for parents and contains a list of books parents can read to/with their children to enhance specific speech sounds.