Click on "Profile" in the left upper corner (middle under the banner).
Click on "Forum Profile Information" in the left column.
you will this this:
here you can
- select a picture from a gallery
- point to your own picture somewhere in the web (this is what I did)
- select a picture to be loaded to the community
The picture needs to be pretty small, around 60 x 80px is a good size most communities except.
After you have made your choice, remember to click "Change Profile" in the bottom right corner.
regards
Torsten