Really quite easy mate, its just using the :hover of an anchor.
set up a list of links (to use as buttons), set the anchor as a block element so that it appears as a button.
then its simple as adding a different background/text whatever on the hover of the link.
eg.
a:link {
background: #000;
color: #fff;
}
a:hover {
background: #fff;
color: #000;
}
This will change the background and text colours of the links on hover.
Look into learning some CSS mate, its great and really helps bring a site on.
Hope that helps,
Edward