Enhancing Your Drupal User Profiles

By Lynn Beighley and Seamus Bellamy from Drupal For Dummies, 2nd Edition

You can allow your registered Drupal users to upload an image that will show up on their profiles. By default, this image is turned on, but to modify its settings or turn it off, follow these steps:

Choose Configuration→People→Account Settings.
Scroll down to the Pictures section.
Select the Enable Signatures check box.

This setting allows your users to create blocks of text that appear beneath every post or comment they write on your site.
Select the Enable User Pictures check box.

More options appear beneath it.

You don't need to change any of these settings. The Picture Directory text box controls where the user images will be stored under the Drupal directory on your web server. The Picture Display Size drop-down list controls the size of the profile image. It defaults to Thumbnail, which is 85 pixels by 85 pixels. The Picture Maximum File Size drop-down list defaults to 30 kilobytes.
Click Save Configuration.

Now, when a registered user chooses My Account→Edit, she will see a Picture section on the Edit form where she can select a photo to upload. This photo will appear on her user profile. She can also create a signature block.