1. You must be logged in.
2. Look for User Control Panel in the upper right, and click on it.
3. Look for profile on the left bar and click on it.
4. Look for Edit Signature under profile and click on it.
5. Type whatever you want to show in every post and click submit button.
6. Look for edit avatar link under profile and click on it.
7. To up load your own file, it must be smaller than 100 x 100 pixels. You can crop or resize the picture in your favorite picture editing program. Click the browse button, locate the file you want. Once you have the picture selected, click submit button.
8. Alternatively, you can click on display gallery at the bottom and choose a preloaded graphic from the gallery.