I like the idea of using AAS for me while keeping it informal and fun for him. Does AAS have a list of rules like "c says /s/ before e, i, or y"? If not, where would I find a good list of these rules? I think that if I had such a list, I could come up with the words. I think I can spell fairly well, but I don't know the rules for doing so.

My 3yo son has been reading for a while, and he likes spelling with foam bath letters. He'll give me a word and have me spell it, and then he wants me to give him a word to spell. I usually just offer whatever word I think he'll enjoy. Should I be doing this in some systematic way? I don't mean should I turn it into schoolwork, but should I be offering words in some kind of logical progression that will help him absorb the rules of spelling instead of saying whatever comes to my mind at the moment?