to do this through Shared Components:
1 - Go to Shared Components
2 - Select Images
3 - Click Create
4 - In the Application option, leave it as "No Application Associated" if you want any application to use the image, or select an application if the image is for that application only
5 - Click the Browse button, locate your image file on your machine and click Open
6 - Any any Notes you want (this is not required)
7 - Click Upload
On your page, decide where you want the image to appear. This can be in a region's Source, Region Header or Region Footer OR if you want you can do this on the page template you are using. Then enter in:
For an image NOT associated with an application:
For an image associated with an application:
http://forums.oracle.com/forums/thread.jspa?messageID=3501716