Just a short little tutorial on how to add your Movies and your iTunes music (from both your local and network machines). This tutorial is using Plex 0.7.5. The seven series of plex is considered a beta right now but there are some exciting additions such as the Plex Media Center (which is currently the best way to integrate iTunes into your music center besides using Front Row or the Apple TV). plexapp.com

More specific info can be found on the wiki.

Adding Media to Library:
wiki.plexapp.com/index.php/Getting_Started#Adding_Your_Media_to_the_Plex_Library

Plex Media Server for iTunes integration:
wiki.plexapp.com/index.php/Getting_Started#Plex_Media_Server