It's really quite simple, once you've singed into facebook go to create Facebook page. In here just fill in all the information.
In terms of design you should not overly get hyped on it. From experience any appearance hacks I attempted got ruined by Facebook intentionally as their updates were geared towards preventing them. Define your custom appearance through your website. With Facebook you can change the images and designs, but you still have to be careful. Read the Facebook Page terms.
There are also attractive services out there that do much of this for you, but they normally charge for the service, take a look at PageModo. I have used PageModo free service, it made the Facebook page appear more like a website by placing HTML custom code in the centre region on Facebook.
Hope this helps.