Link banners on Facebook?

Not sure if this is the right area for this question, but I think it might be the best.

I have a website with links to other music web pages. The members on my site are putting a link to my site on their own web site to be listed for free on my own page.
Now some of them have myspace and more bands only have a Facebook page.

On my site they get a code for my html-banner. But how can they put a link from their Facebook or Myspace back to my site?
Is there a way or isn’t that possible at all?

It would be great to give them easy instructions on how to do it. I’ve been googling around, but can’t find a solution.