Tuck jumps can be a little hard on your knees, so start easy and build up to a full tuck jump if you have never done them before. Tim Ferriss is a big believer of the benefits of Tuck Jumps in his book, the 4 hour body (link).
http://www.bodybuilding.com/exercises/detail/view/name/knee-tuck-jump
http://sportsmedicine.about.com/od/sampleworkouts/qt/Tuck_Jumps.htm