Don't know much about autism / Aspburger's, but I do have dyslexic kids. Highly recommend the Barton Reading and Spelling system. Basically breaks down the English language into a (very long, very complete) set of rules, and then practices, practices, practices those rules. In multiple formats (reading words made with letter tiles, spelling with letter tiles, reading words, writing words on paper, reading longer sentences, reading paragraphs).
You can pretty much do the entire program at home -- assuming you are willing to spend 6-10 hours a week for 4 years. It's a lot, but honestly, it's necessary. And it works. it's probably the only reason my son can read and write and hold down a good job. So I recommend it whenever I hear about a person with dyslexic kids.
Look into it.