For the kid's and the kid in us:
Here's Mozart's famous Piano Piece 12 Variations on "Ah, vous dirai-je, maman" K 265/300e - Composed - 1781 or 1782.
Ok, so you've heard it, it sounds familiar and the first part sounds pretty easy to play. Right? You want to learn it, or you have a kid that wants to learn it - or you are a kid that wants to learn it. Well, check out the score here. It's free.
Jane Taylor (1783-1824) wrote the poem "Twinkle, Twinkle, Little Star" here.
More on Taylor and her poetry can be found here.
Now you know your ABCs of "Twinkle, Twinkle Little Star."