OK, firstly you need to have the pictures hosted online, or if they are already online then that’s no problem. (To get them hosted just search ‘google’ for some picture hosting sites - angel hosting - 81x - a couple I know of)
Secondly you need to obtain the URL links to the pictures, to do this right click the picture and go to properties, this will open a small box and there will be the picture URL, copy that.
Now go to UCERCP and go to EDIT Signature. In there type URL YOU HAVE COPIED GOES HERE[/*img] (remove the stars, no spaces) that should work.
I suggest you read the rules before editing your signature to ensue the 2 you want don’t break any of them.
go to User CP on the blue bar of any page. Then click on edit avatar. There are a bunch of avatars available from WE Forums that you can choose from. Or you can find pics on line and get the URL link to the pic or you can use one from your computer. It is very simple. The max size for the pic is 125 X125.