Leave em to it!
I was recently inspired to pull out the XOs again - they had been sitting on my shelf doing nothing and I thought I should make use of them. Anyway - I've given one to @aspinall for his daughter and one to my son Jaron (5).
I've pretty much just left him to it, and he's steadily working it out.
Anyway, tonight I find him in his room playing around with the speech application. He likes this app a lot, but usually nothing more than typing his name and seeing what silly nonsense he can get it to say. He's not much of a reader, but no surprise for his age and he is a boy!
What made tonight different though was that he pulled out his reading eggs spelling books (which he usually shows no interest in) and is typing in all the words to see how they sound.
What's also cool is that the books are all lower case letters, but the keyboard is upper case, so he's also learning his cases.
So the moral of this story... when it comes to kids and IT... just leave em to it - they'll work it out!