The name of the Webmaster/Webmistress, AKA, the name of the site owner.
The address of your site.
The address of your button.
The E-mail of the person who's interested.

I think that's all there is to it, so, here are my button codes:

<a href="http://www.oocities.org/mx/ccs_anita2002/index.html" target="_blank"><img border="0" src="//www.oocities.org/mx/ccs_anita2002/botonrosa.gif" alt="Hello Kitty's Cottage by Clarissa - Informacion y Downloads para tu PC - English Version with or without frames!" width="88" height="31"></a>	<a href="http://www.oocities.org/mx/ccs_anita2002/index.html" target="_blank"><img border="0" src="//www.oocities.org/mx/ccs_anita2002/botonvioleta.gif" alt="Hello Kitty's Cottage by Clarissa - Informacion y Downloads para tu PC - English version with or without frames!" width="88" height="31"></a>

You can make all the modifications you want, but it's not necessary, you can leave them just like that ^_^.