Family Band video lessons

Learn to play banjo, mandolin, harmonica, spoons, ukulele, etc.

Fun, straightforward lessons.

http://danzanes.com/family-band-workshop

or

http://www.youtube.com/user/danzanesandfriends/videos

(Same videos, different presentation format)

Advanced math practice problems and challenge problems

Art of Problem Solving is not a free site, but their challenge problems section is free with a free registration.

http://www.artofproblemsolving.com/liz/Alcumus/index.php