hi rachael,
my son is 29 months old. when he was starting to crawl, i lined the floor with colorful alphabet (they have them in numbers too, i got mine from wal-mart but i think toys r us have them too) foam puzzle tiles to protect him from hitting his head if he slips and fall. he would constantly take the letters off and show them to me one by one while i tell him the letter names. by 18 months old, (he was delayed in his speech), he will pick out whatever letter (including the color of the letter like blue V, purple T, blue T, etc.) i would ask. at 24 months, we were driving down the freeway and he just started reading the letters and numbers on the freeway sign and cigarette prices in the gas station. today he is reading a few words, most of which he just taught himself, he can read and count up to 40, can recognize all colors and shapes including pentagon, hexagon and octagon, he knows how to write a couple of letters. while i think that those foam letters helped him learn his alphabet, i think that constantly talking and reading and nurturing them can stimulate their natural hunger for kmowledge. these kids are self-propelled. it seems like you are on the right path, keep teaching him whatever he wants to learn.