Check out the plug making tutorial forum below this one. There is a tutorial on a christmas carving that will show you how to hand carve a jointed lure. It can take years to master the art of proper weighting.
I attempted the hand carved jointed one but i was too embarassed to show the final picture.
Alternately pick up some plug building kits from the guys at NJtackle.com
- or cape cod tackle or saltybugger. This will provide some teaching through learning the assembly of the various parts.
Read all of Roccus' tutorials to get a feel.
Not that he's the only builder here, but he has shared his valuable time and vast wealth of knowledge and experience with his tutorials.
They are a must read. Some searching can bring you some more info on lipless swimmers and weighting as well.