I'm not sure what you are asking for.
1. Naming, class/id should say something about an element it is assigned to.
2. If you are certain that only one element will implement styles, then I suggest you use ID.
3. HTML5 adds tags like section, footer, header, aside, etc. Use those (was going to paste http://www.w3.org
link here but I'm unable to connect to their website >.>). Those tags however will not work on browsers like IE8, to fix it just use http://code.google.com/p/html5shiv/
It is up to you how you build your website. Just follow standards and it should be displayed properly on most browsers.