Hi,
If the CFS data are in GRIB format, and they are provided in multiple input types (e.g., 3d atmospheric variables and surface variables), you can follow this example for NARR data, given in the WPS chapter of our Users' Guide to explain the process for the ungrib and metgrid programs:
http://www2.mmm.ucar.edu/wrf/users/docs/user_guide_v4/v4.0/users_guide_chap3.html#_Using_Multiple_Meteorological
The Vtable you need to choose for CFS data is Vtable.CFSR. Hope this helps!