top left of every page, the "user cp" tab
under there you will see "edit's" sig, avatar, profile pic, mail ect, ect.
choose edit signature, chose a pic to upload, or paste the .img code from a pic you uploaded to tinypic or photobucket.com, then paste that into the "edit sig" box, then list your mods under that and click save
should show up in all your posts
holler if you need more help
edit avatar for the pic by your name
not sure how this all works on a phone, may need a pc ????