This all depends on what exactly you want. Are you going to be using an image? Pure coding with some kind of background colour? Text? No text?
I mean, for example, you could use this which is just a simple coloured background with text - for a signup:
Code:
<!-- BOTTOM FOOTER SIGNUP-->
<p style="position: fixed; bottom: 0px; left: 0px; width: 100%; height: 45px; border-top: 2px solid #191919; background: rgba(25, 25, 25, 0.75); -moz-border-radius: 0px 0px 0px 0px; -webkit-border-radius: 0px 0px 0px 0px; z-index: 100;"><a href="http://chaturbate.com" style="display: block; color: #FFFFFF; font-weight: bold; text-align: center; line-height: 45px; font-size: 200%;">CLICK HEER TO SIGNUP</a></p>
That would produce this simple thing:
View attachment 82832
It would be fixed and follow you up/down the page
If this is not it, try to be more specific, please.