I don't know your son's exact age, but we began with the Baby Signing Time (all ASL signs) DVDs with our HOH son at 5 months corrected (He was a preemie). I limit his TV use, so he only watched at most twice a week for well over a year. However, he loved the DVDs. He loved the flashcards that went with them too, getting them out and flipping through them one by one, or bringing them to me to do the same, when he was barely walking. He can sign over a hundred words today, at 2. We also have two little ASL sign books for babies that he enjoys. I have studied up on some sign via the DVDs and an online dictionary, and am now over 500 words. Signing gives Andrew a good way to express himself if he can't say the word he wants. He only signs many things, like sorry, thank you, and please. He also uses a combination of sign and verbal words to help us understand. And signing/verbal combos were among his first phrases, like signing shoes and saying "o--" for off.