Safari HTML5 Audio and Video Guide: About HTML5 Audio and Video. This is a good reference with lots of sample code for using HTML5 audio and video. The samples cover a wide range of possible custom applications. Though it's specific to WebKit/Safari, many of the CSS styles used for custom appearance are now supported by Firebox and, of course, Chrome (which is a WebKit browser like Safari).

How to play sound from a web page - UCL. From a website devoted to speech, hearing & phonetics, this is an excellent rundown of the various ways webmasters can add an audio file to a web page. Great examples and clear code for each of the 10 methods.