katierocket - 2 isn't necessarily too young, depends on the child though. Is he good at jigsaws, recognising shapes, spot-the-difference, etc?
Personally - having used both - I would recommend Letterland for a child this age, but am obviously in a minority here. My boys both started reading at 3, and were pretty fluent by the time they started doing any sort of letter formation (about 4.5), so they didn't start drawing faces in their letters, as some describe here. I think 2 and 3 yr-olds relate well to the letterland characters. Also the names really help you to get to the real sound of the letter. JP is excellent if taught well, but many parents still come out with 'cuh cuh cuh' rather than 'c c c' ... it is VERY DIFFICULT to get a pure consonant sound - which is why letterland doesn't try.
If you want to start with letters, do one or two at a time. If ds has a short name, then start with some letters from his name. To move on good letters are s a t i p n, as these are some of the most frequently occurring in CVC words, so with those six you can make lots of words.
Play loads of matching games, colour big pictures of the letters, I spy is great, make a sound scrapbook together - one page per letter with lots of pictures to match. but make sure you stay phonetic - don't put chair on the c page, or shoes on the s page. If you have any of those simple letter pair jigsaw things, then just pull out the half a dozen you're currently working on, and practice matching them, etc., etc. Letter learning can be fun, and if they are ready for it, 2 is definitely not too early, and you will be giving him a real advantage.