The best way is to start from the beginning, in other words read "Smashing the stack for fun and profit". These technics doesn't work on current operating systems but gives to a great start http://insecure.org/stf/smashstack.html
Better to link directly to the source ( http://phrack.org/issues.html?issue=49&id=14#article ). Phrack Magazine is a great piece of history of the underground. Even today reading some of the articles provides good insight. After all, the essence of the computers architecture has not changed in all these years.