Get Familiar
Use Filters to find Videos, Playlists or Channels
Advanced Search Explained here
YouTube customizes your "start page" based on what it thinks you want to watch. Toggle to "social" to see the videos shared in your Google+ circles, by your Facebook friends, or by those you follow on Twitter.
Components of your One Channel (YouTube Help's Playlist)
Create a YouTube Account
Go to Youtube, and then sign in using your Google Account. Hit the upload button and follow the prompts to get your channel up and running.
Search for Channels by Topic
Search for topics related to your teaching. Are there channels out there that look like they might be producing stuff you can use?
Start Subscribing!
Subscribe to excellent content (either my suggestions above, through search, or by browsing Youtube/edu or YouTube/teachers
Advanced: One Channel Housekeeping
Get your "One Channel" up and running by adding artwork, links to your social networks, and tweaking sections.
Discuss: Subscribing, Connecting, One Channel
Does this fit in your class? Should students have this portfolio? How could you harness the social features?