Some of us from our company have normalized the best practices around and kept on GIT, you can use the below link to access the same, we have made it public recently.
It's not about the html semantics only, you could also found the same on JavaScript, CSS and Accessibility too.
http://sapient-global.github.io/best-practices/
GIT - https://github.com/sapient-global/best-practices
Other then you can find the below links useful:
- http://isobar-idev.github.io/code-standards/
- http://net.tutsplus.com/tutorials/html-css-techniques/30-html-best-practices-for-beginners/
- http://google-styleguide.googlecode.com/svn/trunk/htmlcssguide.xml
Last but not least, always do validate your html using W3C validator to do the sanity check.
