Again, assuming you're in the U.S., there's a lot that can be done. Every campus is required to have an office (or at least a staff) that deals with the needs of students with disablities, so they'd be the ones to contact. They can't help him get accepted to college, but they can help with things like extended test times, testing in a private room, notetakers, assistive technology, etc.
For financial aid, call the financial aid office. There's a lot of federal assistance available, and depending on where you are, some states offer help. You might also contact your local Vocational Rehablitation office. I've known quite a few people who were able to get money from them to go to college.