Feel free to keep asking as the help section is a bit sketchy so far...
As for the Icon by your name in the Forums you have to go to wincustomize.com and set it up there (it is tied into JU you see).
The picture? Well you can put that in there just like you put in links to others blogs.... look at chip's for an example
hmm that is a darn good question! I just tried it and haven't figured it out myself.