If you are not going to carbonate with your co2 tank, then yes you need to use the priming sugar. If you are going to put the keg in teh kegerator and hook up the gas and leave it hooked up then no. Just hook up the co2, purge a few times, then set it at 10-12psi and leave it hooked up for at least a week.
Primaries: Mojave Red (AG)
Kegs: Hibiscus Saison (AG), Orange Kolsch (AG) , Cocunut Porter
Future Brew: Wee Heavy