"Tech Writing Handbook" by iFixit

© Ugur Akinci
Here is a “Tech Writing Handbook” for beginner technical writers.
It’s very visual, pretty, looks great. Has high eye-candy value. It also covers the basics nicely.
http://www.dozuki.com/Tech_Writing

 
However, if you’d like to go deeper and learn more about all these topics while doing exercises, answering quizzes, and writing a User Guide along the way, then I’d recommend our “Technical Writing and Editing” online course.