Adding a profile picture, or avatar, is simply a matter of editing your account again. Hover your mouse over my blog, and you'll see the drop down menu, including "my account." Go to your account and edit it. Scroll to the middle of the form and you will see an area titled "picture." Click the browse button, and you will be taken to your computer's finder. From there you can select and picture you want as your profile picture (it will be automatically resized). Then you simply have to scroll down and click save.