Start small and work your way up. You can do some simple phone videos to get used to what you would like to ultimately produce.
I dislike the webcam and "music" camera videos because of the fisheye effect they produce.
Check out this current topic:
http://www.acousticguitarforum.com/f...d.php?t=491629
You should also go to Fran Guidry's Homebrewedmusic.com which is an excellent resource for creating "Look At Me Play Guitar" videos.
http://www.homebrewedmusic.com/