Using Resources - is there a reference guide with examples ?

I've hunted and have not been able to find a reference guide to the Resource compiler and the files it expects.

My first try at defining a "resource" that would simply define a font size that might be specific to a given watch or watch family failed and produced a lengthy set of errors from the resource compiler, including a list of tags it expects. 

While that is a somewhat helpful, it is a far cry from seeing a reference document that tells me what the resource compiler accepts and what it does not.

I've looked through all of the documentation I can find and don't see anything that defines what can an cannot be in a resource file.

I am not trying to define custom fonts. I just want to define the standard fonts that will be used for given fields in my app, in a given watch or watch family.

So... is there a reference guide for defining and using resources ?

Maybe the simpler question is... is there a way to do what I'm trying to do using the contents of resource files and Rez, and if so, how ?

Thanks