Newbie question - what schema should I use?

[Jose Gonzalez Gomez <jgonzalez@opentechnet.com>]

    Hi there,

    I would like to use docbook as the format for the documentation in 
several projects I'm working on now. The idea is having a set of related 
documents, in a tree hierarchy, containing, among other things, the 
requirements of the application specified as use cases. One of the 
things I need in this documentation is to be able to link to other 
documents, so I don't have duplicated and/or bloated specifications, 
making the documentation more readable. So now the questions:

    I thought about using the simple docbook schema, as I don't need a 
lot of the things that appear in the whole schema, but this schema 
doesn't seem to support linking between documents. So what's the best 
solution? Should I go for the whole schema? Or is there any way to link 
between documents using the simple schema? (I forgot to mention... the 
main output format will be html). Maybe instead of having a lot of small 
documents I should have just a dockbook document for the whole 
documentation set and generate from this several html documents with 
links to each other? How can I achieve any of the above (I mean, what 
tools should I use)?

    Any advice would be greatly appreciated.

    Thanks in advance, regards
    Jose