advice on grounding lamp and ballast required
Normally the cord attaches to the fixture or to a multiwire splice that connects to the housing and to the ballast if the ballast has a grounding wire or terminal. If the ballast doesn't have a ground wire or terminal the ballast is just grounded to the fixture housing by it's mounting screws. 

The ground wire on the cord usually attaches to a designated (green) screw on the fixture frame. If the ballast has no direct ground connection then you can use a blue (for #14 and #16 wire) stake-on fork on the stranded wire from the cord and attach it directly under the ground screw or you can wrap a short piece of solid green or bare #14 wire around the screw and attach it to the cord by a wire connector. 

If the ballast has a ground terminal or wire that connection is not adequate to ground the whole fixture by that ground connection. Normally you would connect a short piece of bare or green #12 or #14 wire to the fixture ground screw, then use a wire connector it to the ground wire on the cord and the wire grounding to the ballast.