My ds is 10 and was dxd when he was 8.
The three most useful books we have bought have been:
Can I tell you about Asperger Syndrome?
Different like me. My book of Autism Heroes
and more recently
The Survival Guide for Kids with Autism Spectrum Disorders
He chose not to tell people at school at first, but has now told his best friend and one other child whose sister also has AS. I think this was a wise choice as, whilst the other kids in his year can't fail to notice he is different and needs more support than they do, there are certain pupils who would almost definitely use a dx as leverage for bullying and teasing.
We talk a lot about how the world needs people to be different, as it means we all have different strengths and therefore have different things to contribute. If we were all the same, everything would be mediocre, bland and boring, there would be no incredible art or science breakthroughs or incredible medical/surgical procedures etc. I have explained that no-one is good at everything and that we all have some things we are good at and others that we struggle with and then talked through his specific strengths etc with him and explained that that's why he needs more help with some things than some of his classmates do - but then again, they aren't amazing with facts and computers like he is.
He is still taking it all in, but we have an open dialogue and he asks questions on pretty much a daily about what having AS means for him and whether or not certain situations were affected by him having AS etc. He has days when he says he hates having autism, but on the whole he appreciates that it has both good and bad sides to it.