Signing the "ing" and word endings, from what I know, is very English, and is not ASL. You should try to find a good ASL Grammar book from your Library.
It is hard learning this from just books, but learning how ASL grammar works will help you a lot. I've been teaching myself from books and videos as well. Luckily I have made a few friends in the Deaf community and that has helped a lot! I also got several good books from Amazon.com that explain ASL Grammar.
God Bless!
