
In this technological age, where everybody has access to computers, learning to type well makes sense. You could be a "Pick-n-Pecker" who uses only the index fingers to make it through whatever typing has to be done, or you can be smart and learn to touch type. Since technology is not going away, I would recommend teaching your children to touch type.
I am old-school when it comes to typing software, and in my mind, you can't beat Ole' Mavis Beacon , whom, I am disappointed to find out, isn't a real person! I have always hoped that Mavis Beacon was a retired typing teacher who was living very quietly and filthily rich, in Ohio or Indiana somewhere, and would someday surprise the snot out of her relatives when it was time to read her will.
Anyway, Mavis Beacon costs about 20 bucks new, and can be borrowed free at the local library. It locks in touch typing, and once you get it down, you will increase your typing speed and accuracy. Even adults can learn it easily with regular practice. It's best for kids 12 and older, but one of my children, who likes getting the facts without any embellishment, used it when she was 10 with no problems.
Another good system is Typing Instructor for Kids. It's also about 20 dollars, suitable for younger kids, and is more fun than Mavis Beacon, if fun is what you are after when learning to type.
Once your child has gotten the basics of touch typing, go to Learning Games for Kids and have them try some of the typing games. Dance Mat Typing is good for beginners, Alpha Drop is a Tetris-like game that helps with letter typing, Cup Stacking is a fun game for beginning typists -- an extra challenge is to suggest that the child not look at the keyboard when he is typing.
My favorite game is Typing of the Ghosts. This is an addictive game that can be played by children and adults alike. It is also Tetris-like, but this time words instead of letters that you must type before they hit the ground. As you expect, the better you do, the faster the words fall. It is also timed.
Nothing wrong with having a little fun while you learn!