Ok, Im new to css.. I was wondering if Im shapost to mix this with my already html code or code a whole new layout? Also, can I mix css with php.. What does css do, exactly?
It presents and formats the content in your HTML (at least that is what it was intended to do until people introduced formatting markup in HTML). CSS gives you more power over presentation. CSS can be "mixed" with PHP in the same way HTML "mixes" with it. Not sure where to go for more info and a better explanation, maybe try http://w3schools.org
You seprate your CSS from your HTML by serving it as an external file in the HEAD section of your Web page via the link element: <link rel="stylesheet" type="text/css" href="/styles/screen.css" media="screen,projection"> Code (markup): SitePoint has some wonderful books and articles on CSS, why not give them a try?