Specifications
OASIS WSRF Page: The most recent version of the WSRF specifications can be found here.
Globus WSRF Page: Contains pointers to papers and presentations related to WSRF.
Official Globus Documentation
GT4 Fact Sheet: Everything there is to know about GT4.
Official GT4.0 Documentation: Includes the installation guide.
Other related documents
Ian Foster's Globus Toolkit Primer provides a detailed look at the toolkit and all the components included in it.
Scott Gose's WSRF Grid Services page. Includes easy-to-understand instructions on how to set up a minimal WSRF container.