bones and realistic human rigging

I’m new to blender and i want to learn how to make a realistic human for animations and games. Also can some one teach me about bones cause i don’t know how to use them.Is there a tutorial on rigging.

check out all the useful tutorial links here

http://en.wikibooks.org/wiki/Blender_3D:_Tutorial_Links_List

under Armatures and IK heading