It depends on what you mean, Lawrence. If you mean an avatar (the picture beside your posts) then you are limited to those provided by the forum for now. you can read up on it here.
If you mean posting a picture in a post then you would have to host the image somewhere and use [img][/img] tags around the URL.
It has been a while since I messed with the Albums feature so I don't remember offhand how to go about it. If this is what you mean post back and I will look it up for you.
When you're posting:
Go Advanced
Then scroll down and you'll see a "Attachments" header with a "Manage Attachments" button.. if I understand the question correctly