Having the ability to type without looking at the keyboard is the most important factor in achieving a fast typing speed. Even if you have memorized many of the keys, unfamiliar keys will slow you down just like speed bumps on the freeway.

TypingClub is the most effective way to learn how to type. It is web based and highly effective. TypingClub is (and will always be) free for both individuals and schools. There is an optional paid school edition. Get Started Now

Don't rush through -- trying to type faster than you are capable usually results in more mistakes. Only type as fast as you can comfortably type for whatever word you are attempting. For commonly used words like "the", "and", etc.