For how to write a form that you can easily style with css, look
here. Basically, you put a <form> tag and any text boxes ect inside it will then send their data to where you tell them.
As for processing, you just need to play with $_GET/$_PUT, and then MySQL databases, unless you're going to pay to have mail() enabled.
Sorry, this isn't very detailed, I'm in a rush. I may post later.
swordz