Are there any good resources out there that I can use to help teach my 7 year old about 9/11?
Yes, you can buy a movie called United 93 and this will help your son understand what happened on that day. By watching this movie, your son will have an idea why this day is special to every American and why memorial services are held.
Library and they have a special coming on the day of September 11th sit ya child down and explain
I think a 7 year old might be a little too young to learn about religious hatred causing mass slaughter of innocent humans.