Mr. Softy wrote this and I am reprinting it.
You just have to click on your name up in the right upper corner and that will allow you to edit your profile. You need to have a graphic that is Square (default dimensions are 100x100) and it should not be very big in size (10-20 KB).
In the edit profile place you can choose the avatar tab and click the browse button and find your graphic on your PC and then click the Update button. Then when you are done, you click the Save button and you should have your avatar.
Mr. Sweepy