Oddly enough there is another discussion on this topic where you can find some advice. If you already have an AdSense account, you can learn from their user interface in your account. You can read about that here: [webmasterworld.com...]
Google explains how to set up their search on your site, and all the benefits, rules and limitations of it here: [support.google.com...]
Since you are asking about Search style, it is up to your css skills to style the appearance of the elements on your site. Basically it is just a search bar.
