How do I customize my theme?
First off I'd recommend using a Child Theme, some of my newer themes come packed with a Child Theme Generator (http://www.screenr.com/tbos). After you've created your Child Theme you're ready to start adding your own custom CSS. The easiest way to find what styles do what is to use either Firebug or Google Chromes Developer Tools, to inspect each element of the theme through the browser. Take a look at this great screencast my friend Brandon Jones put together below and also checkout this article https://premium.wpmudev.org/blog/chrome-developer-tools/