I am surprised that mom and dad have not given you any resources to deal with these issues???
Those are some great websites that Skysue posted, definitely check them out.
The most important thing I have seen in dealing with kids on the autism spectrum is PATIENCE. They process information differently and express thier own feelings, etc in some different ways. The one thing I will caution is that you learn what you can and cannot expect from him in terms of behaviour. Do not allow this aspect of him to be the ruling factor in how you treat him, simply a thing to consider. Do not allow it to be a crutch for bad or inexcusable behaviour (ie; aggression is not tolerated... period! regardless of the fact that you are "autistic"). I have seen this happen so very often, that a diagnosis of autism becomes a reason to no longer parent and then the child begins to control the relationship. Not good.
I would for sure have a discussion with mom and dad to find out where they stand on it all.