How to explain Autism to children

Being a mother of a special needs child and they have a sibling that isn't, many people ask me how did I, do I or will I explain Autism to my childs sibling or others. Honestly at first when his sister started to ask why he did some of the things he would do I would tell her things like " Seany like many other kids is a little different than you so he does things and sees things in a different way." With research, resources & etc that eventual evolved to " Seany has Autism which means his brain thinks and does things differently than yours and mine, some things your brother has trouble doing so we have to help him but there are also amazing things your brother can do and we should always cheer ." We talk about Autism often so our daughter and extended family young and old are familiar. For those that want to have resources or link to help explain Autism to children or simple terminology here are some links:
http://kidshealth.org/kid/health_problems/brain/autism.html
http://thirning.blogspot.com/2010/08/explaining-autism-to-classmates.html