Christian Heilmann lays out seven rules to better unobtrusive JavaScript, including not making assumptions about JavaScript, the browser and the document. Work with structured markup. If you are traversing a document, maybe there's a solution that can take advantage of CSS's selector mechanism instead. Work with browsers and users. Better understanding of events, and playing nice with namespace, scope, and patterns. And of course, think about the next developer, so keep the code maintainable.
A table that lists CSS style properties and their JavaScript equivalents. Useful for dynamically setting styles in JavaScript, although the better method, if possible, is to use classes instead, and those classes are styled with CSS. A few are missing, like float which is a reserved word in JavaScript.
A list of the CSS Selectors supported by jQuery. It includes the regular gamut of CSS selectors as well as attribute selectors, pseudo-selectors and child selectors.