Concept of Gravity

I use to think that heavenly bodies were like magnets that attract each
other. That was my concept of gravity. Now I realize that gravity is more of
a space-time continuum. Problem is that I barely grasp this concept and was
wondering if there was an illustration somewhere that would help? Perhaps
this can be found in a text book or online? Homer Simpson's skit was great
but I need something more serious and comprehensive. All comments are
appreciated. Thanks.

west