After you send your CV, if they think you'd be eligable to work for their company, they will call you and set up and interview. You basicly should be your self when going to these interviews, but don't be your self too much. Dress up for the ocassion.
It is scientificaly proven that blue is easy on the eyes and you should always wear it when going to meet up with a potential employer. Wearing blue (light blue in particular) gives the impression that you are an open person, one that is easy to comunicate with, somebody that is trustworthy, or to shorten the story - an OK person and potentioanaly good employee. Never wear dark colors, especially not black!
Don't talk too much, but don't be quiet all the time. Show your tallents, don't brag about your floods, and that is about all you need to know.