To set your avatar, your signature, and other settings like that, just click on the icon at the top of the forum that looks like a gear.  That will take you to the user settings screen, where you can configure to your heart's content.  I've got it all working now, at least as near as I can tell.  As always, please let me know if you encounter any problems.

Not thick at all.

Click on the icon at the top that looks like a gear, that will take you to the User Settings screen.  There are several sections there, and most of them are collapsed.  Expand out "User Settings", which is the third section.  The last line there is for your avatar.  There is a drop-down list, which is probably empty for you.  There is also a textbox with a browse button.  Click the browse button, and browse to the avatar image on your local machine.  Then click "Upload New File", and it will upload the new file.  I think then you have to go back to that drop-down and select the file from the list, and then click "Add".  You should then see the avatar image appear above the drop-down.  Once you have done all that, click "Update" at the very bottom of the screen.

Turns out I had a configuration setting wrong.  I was seeing it because I am an admin, but when I looked at it in my fake, non-admin, Dewey Cox disguise I could see what you are talking about.  It's fixed now.  Instead of a drop-down, you see the browse button.  Take a look, let me know what you think.