Good Library of Cheat Sheet Guides
Single page reference sheets - often called Cheat Sheets - are good reference guides to common tasks. Most developers have used them when researching the latest CSS styles or figuring out the proper regular expression.
A great online resource is the Cheatography website - they have a huge selection of cheat sheets in various topics. If you think you can do better than what they have, you can also create your very own cheat sheet.
Description from their site
Cheatography is a collection of 4,488 cheat sheets and quick references in 25 languages for everything from business to food!
The five most popular Cheat Sheets:
- Regular Expressions Cheat Sheet
- Linux Command Line Cheat Sheet
- EQ tips Cheat Sheet
- Python Cheat Sheet