[natemartin]

Well, do you know the basics? HTML and CSS? Pretty much all the custom buttons, menus, etc you see are just clever HTML and CSS, with some well placed images.

Are you asking how to design a button in, say, a graphics program? Or are you asking how to turn an anchor into a fancy looking button using CSS?

[pbhjpbhj]

What he said - menu's and buttons are just links and lists of links with styles applied.

If you're doing fuller apps you might want to look at Yahoo's YUI?