My son just turned 18 Monday, and he will be graduating on Tuesday. The special needs program he is in at school has been very helpful in Zack's transition to his new school. He even got to tour the school he will be attending next year, and his teachers have been helping prep him for the change with discussions and activities. We have also assured Zack that his summer will be the same it always has been. That makes him feel comfortable. I would see if your sons school could help you out as well.

Look for support groups that plan teen outings and keeping a calendar with planned events help my 18 year old daughter.