Document field definitions

I'm developing a widget which queries for a bunch documents and creates a grid using a repeater.  I've spent a full day trying to find what fields the document module has that I can use to filter and display, and I just can't.  Is there anywhere with a list of api names for the document fields?  Currently, I'm trying to do something like this to filter the document by library: 
librariesManager.GetDocuments().Where(d => d.Library.Id == library.Id);
I also need to find a way to create a link to the object, but can't find any definition on how to do that/where to find that.

Suggestions? Thanks