Dance Mat Typing - This is a fantastic program for young children (Grades K-4). This program from the BBC, is geared toward beginning typers. There are different levels that focus on specific keys and after each successful level, students are rewarded with a song and dance.
Keybr - Quick, basic, and easy to use. Keybr tracks your speed, errors, and keys that you are struggling with. Another nice feature about Keybr is that you can type the content from any website by simply entering the url of that site.
E-Learning for Kids has a space theme that makes it fun for kids to practice their keyboarding skills. Games can be unlocked as typists move on to higher levels.