typingweb.com is a website for learning typing and getting certification, its interface is really good and user friendly and it's also a web application which means that you don't need to install anything on your computer, the only thing you need is a web browser.
The certification is not free, about $40. So if you don't want to become a typist it does not worth it, and if you want to become one then make sure that the certification is creditable and accepatable by employers.