It is important to keep children with Autism engaged academically and socially. If a child is left hours at a time stimming or playing video games, this just allows them to retreat further within themselves. Some Stim time should be allowed but limited.
Temple Grandin recommends the book Early Intervention and Autism: Real-life Questions, Real-life Answers by Dr. James Ball
This book provides information on interventions, teaching strategies, program planning and behavior management.
Sources: The Way I See It by Temple Grandin PHD