I found this free text expansion app invaluable for detailed, technical writing. It prevented mistakes while speeding up my typing.

Stamina Typing Tutor is a fun-filled free typing software for adults and kids. Learn typing on your PC using this typing tutor.

Whether you're an able but slow touch typist, or you never graduated beyond hunting and pecking, TypingWeb is a free and easy to use online typing tutor that will help you hone your keyboard chops ...