South Central is about as close to being a gym as an outdoor crag can get. It's bolted to the beejesus (with ring bolts and brackets - no crappy carrot bolts here!), and sees all sorts of gym-like antics from its inhabitants. It's also the home of such legendary climbs as "Sperm Bitches" and "Dungeon Master" (both 31), and such legendary feats as Saxon Johns' solo of "Ain't No Sunshine When He is Gone" (28).
To get to South Central, park at the end of Jamieson Road and walk straight ahead down a slightly overgrown path until a small waterfall is visible to your left (about 30m from the carpark). Cross over the creek at the waterfall and continue along the track for about 15m until you emerge in steep, chalked roofland.
A note about grading: I had heard that Nowra climbs were generally (and in some cases severely) undergraded. From my (somewhat limited) experience, I'd say that the grades are all pretty fair, being comparable to Blue Mountains grades (Mt Piddington is the crag I usually measure against). In any event, if you're just leading Sydney 16s, a Nowra 16 might leave you hanging from the sharp end of the rope.
The guide for the area is the "Rockclimber's Guide to Nowra & Wollongong". There is also a "Rock" magazine update available, which is well worth getting.