Joomla Website Template

now Designing a simple Small Business website in Joomla. Most of the designing I can do once I have an effective template. All graphics will be provided by me. I want a simple design, with notes in the html and css pages to guide me when I need to make changes, such as changing my header. I know basic HTML and PHP so I'm not looking for explanation of how to change just notes telling me where to make changes for particular items so I can find them for quick changes. I'm Looking for a 3 column template, with my banner and logo on top. Left and right sides will include modules and center will be for main content. I'm willing to pay for the template so I won't have to put a link on the page. As I said I want a simple template that I can change as my business grows and changes.