I would go with recognition first, then move to writing later. Depends on their own ability really, some kids just won't have the fine motor skills at 3 to be able to write (and they get super frustrated and turned off it if they can't do it right). Others can write early.

We read alphabet books, ones with the letter and heaps of pictures/words starting with that letter. There is a good song, The Phonics Song on you tube be KidsTV123 which is good and fun.