If you find yourself instantly referring to Codex or looking for a commonlyl used template function, consider using this WordPress Cheat Sheet.
Launced in February this year, this WordPress Cheat Sheet created by Trevor Niemi has listings of functions that you can copy and paste into your work. Some of these functions are linked to their corresponding Codex page for more information and its general use. You can also download the PDF, making it easy to save and view information when you’re offline.
Since its launched WP-Cheatsheat has received more than 15,000 total visits with an average of 100 visits per day.
Read the rest of the post here: http://wptavern.com/wordpress-cheat-sheet-for-commonly-used-template-functions