How you get a sig...
A) Ask for one
B) Tell them the specifics on what you want on it
C) Wait
D) see if you like the finished product
E) if you dont like it tell them whats wrong and if you do then you right click on the pic and you can either download it to your computer and saving it with paint or you can copy the url of the image
G) Now go to your controls and click
1) Edit hosted signature settings and upload it from your comp.
OR
2) Go to your signature settings and type [img.] Paste the URL here [/img.] withought the two .'s in the brackets.
Click update settings and your done. The hard part is getting a signature you like.
If you want to get a sig ask a known sigmaker (me/other people) or go to a sigmaking thread.