George,
If you go to the different FTP sites listed on the PCGRIDDS32 Home Page, there you will see different subdirectories for the different models. This Web site:
http://strc.comet.ucar.edu/gribmaster/modeldatasets.htm
has a good reference for the contents and sizes of the different model GRIB files. The Web site listed in the previous post was a 'bit' wrong. It should be:
http://nomads6.ncdc.noaa.gov/ncep_data/index.html
(without the trailing period [.]). I'm sure it is good for smaller data sets but i have not had luck using it.
Wherever you go & however you do it, the GRIB files need to be downloaded into the PCGRIDDS32/GRIB/NWS directory. once there, run the NGRB2PCG32.EXE utility to ingest & convert the GRIB file(s) to PCG (PCGRIDDS32) format. You can then start up PCGRIDDS32 to open that data file & work with the data.
Good luck,
Jeff Krob
PCGRIDDS32 System Developer