You picture wasn't bad. Some that don't resize fill up the page and then some which then causes the text to go wider than the page. I guess it depends on the resolution you set you're camera at.
Resizing is simple. After you've downloaded you picture you look at it. Above you see some options. Pick EDIT. You'll get more options and one is resize. Click on it. You'll get more options which includes avatar, message board etc. Pick message board and you're good to go.
If you want to post your own avatar select that and the copy and paste in you profile.