A banner for placing at the end of each of your posts? That's a do-it-yourself thing. There are some members who offer banner-making services here, but otherwise, you're gonna have to create your own via Paint, or maybe a more advanced program such as Photoshop (which costs money).
If you already have an image you wish to use as a banner, simply click this button:
(This link can also be found near the top of this page). Then, on the left side, go to "Forum Profile Information" and scroll down to where it says "Signature". Then type this in.
[IMG]PLACE URL TO IMAGE HERE[/IMG]
Here's an example.
This...
[img]http://www.capturedwings.net/forums/Themes/SS%20returns/images/banner.jpg[/img]
...will turn into this:
The image
must be on the internet somewhere; you cannot pull it from your computer with this method. If you want to, you can use a utility such as
http://www.photobucket.com to upload images from your computer to the internet.
Hope this helped!