Hello Todd,
You can download the newest IFC add-on from the next URL:
http://www.graphisoft.com/support/ifc/downloads/public/
If you install it you can find IFC user's guide; "IFC_Guide_2xEd2_v3p5.pdf" in the "<ArchiCAD folder>/ArchiCAD Documentation" folder
Anyway it is recommended to download the last IFC add-on from the above URL because the IFC add-on in ArchiCAD package is 1/2 year old and we corrected some bugs in the newer version.
Regards,
Gyula