category (or other method) to link pages

Any suggestions on using Categories vs manually linking pages together?  I am not sure if Categories are the best or not, but it seems to be some of the most frequent edits (adding categories, removing categories, changing cateogy names, etc).

The only reason I like the categories is they automatically list all pages linked, so it is easy to build up a structure of related content.  EX:

vital resources

-> water

    -> water extractor

    -> water tank

etc.  I find the more content links to other content, the easier it is to find related, relavent information.

Does anyone else have thoughts?  I was just doing what is easy but it is important for us to find consensus and maintain consistency.