Have your kids join activities they already enjoy. If your child likes chess, have them join the chess club, not Boy Scouts.
What the Research Says...
Play your own version of Charades. You can modify for all the kids. Or play modified Pictionary; you can modify by drawing them first with basic shapes and have the kids copy, while the others guess.
Build/create a board game based off favorite activity (Minecraft, Dora, etc)
VB-MAPP Great assessment that includes social skills
Crafting Connectionsuses ABA to teach social skills
Interview peers within the group. Start with 3 questions, have them make up 2. Write or draw responses. Have the interviewer introduce the child to another child using the interview sheet.
Article on how to make friends.Autism can be your child's ally, not enemy, in making friends: 5 tips on turning peers to pals
The Giraffe with Autism
A Children's Book Series