Customizing templates

Are there samples somewhere of all the various bits of basic code to alter when creating custom templates (any template -- maybe the "Logo and Tabs Template" within the Website Theme, or an "Item and Category Template", or a "List Cell Template"...) I'd like to know what code is there in the basic NetSuite design. With sample code to start with, I can do simple layout and design adjustments.

I've stumbled my way though this many times -- we use a lot of custom templates on our site -- but it's always a huge ordeal. I usually view the page source, and then start hacking away till I figure out which bits belong to the template. The inline Helper text usually just says "Must contain..." or "Must start with <td>...", but doesn't give the whole story.