Council for Exceptional Children is a website for all areas of special needs. https://www.cec.sped.org
Dr Temple Grandin is one of the most famous people with autism in the world. She often speaks at the Future Horizons conferences. She also has books including Thinking in Pictures, which was made into a movie. https://www.templegrandin.com
Dr Antony Attwood is from Australia and an outstanding speaker on autism spectrum especially Asperger's or high functioning autism. He also has a website and books. He is very knowledgeable. http://www.tonyattwood.com.au
Jed Baker has a website and great books. He is knowledgeable on behavior and social skills. http://www.jedbaker.com