jQuery Selectors Cheatsheet

The people at Refcardz have a great cheatsheet on jQuery Selectors (.pdf).

jQuery selectors are one of the most important aspects of the jQuery library. These selectors use familiar CSS syntax to allow page authors to quickly and easily identify any set of page elements to operate upon with the jQuery library methods. Understanding jQuery selectors is the key to using the jQuery library most effectively.

Also, checkout all their other free cheatsheets as well.