custom style [how-to] wanted

[Sculli]

Does anyone know of a good tutorial that explains how to create custom styles? I found the download for the default gfx psd files, but what I am looking for is something that will explain the CSS and whatever else there is to know about it.

I googled, and I searched here, but the result was information overload.

Thanks in advance for any help you may be able to provide.