Sounds like you should watch the introductory calibre videos and tutorials, they cover this stuff. See the sticky in the main calibre forum.
There's also this blog post:
http://blog.calibre-ebook.com/2011/1...g-browser.html
Also keep in mind that what you quite possibly want is to make use of a feature in calibre called
hierarchical tags. This is all described in the calibre help.