I've used a number of online courses and I still refer to them but for clarity and depth this one has become my favorite by far:
http://truefire.com/tftv/index.html...le=mp4:ukulele-guitar-players-videos/mmufg-01
http://truefire.com/tftv/index.html...le=mp4:ukulele-guitar-players-videos/mmufg-01
