Trouble getting the bones to move the mesh correctly

I’m having trouble getting the bones to move the mesh correctly. For instance:

First I selected the upper_leg bone. Then I deselected the the vertices on the upper_leg bone. Then I click on remove. Then I go to pose mode. But when I go to rotate the upper_leg, half the body moves with it. I had better luck with the left foot, but the bone popped out of the foot when I rotated it. I included two screenshots to help show you what I’m doing (or not doing). Can anyone help me out?

http://i1130.photobucket.com/albums/m539/Blanco111/Works%20in%20Progress/th_help1-3.jpg

http://i1130.photobucket.com/albums/m539/Blanco111/Works%20in%20Progress/th_help2-2.jpg