There are many audio files available online. If you'd like to muck about, here is a good listing of links at About.com: http://poetry.about.com/od/audiopoetry/Audio_Poetry_Archives_Anthologies.htm
Otherwise, if you'd like the best, broadest collection, I'd start with this site:
The American Academy of Poets
http://www.poets.org/page.php/prmID/361
For videos that include poetry recitations, visit the favorite poems project site:
http://www.favoritepoem.org/videos.html
