Some one please help me figure this out.

Hye I feel a little jelous all you people have some cool sigs. By the way what is the deffintion of a sig and what purpose does it serve.  Anyway I need some one to tell me exactly step by step on how to make one of these for my self and then how to put it in here on these forums.  I want to be cool like the rest of you peoplz.  Thanks and by the way give me instructions like a how to for dumby books yes i can be that dumb thanks in advnce.

I also want to know how the pics work with the sig.  how do you make them with all those cool graphics and the codes and the different affects and such.