I can't say that I've done Goulburn to Maitland in one go, but I've done all the constituent parts. I think that the easiest way is around the west side of the range, turn left somewhere north west of Mudgee and come down the valley (and admire all those lovely coal mines...). Alternatively, go via Mittagong, The Oaks, Prospect, up the VFR lane to Mooney Mooney and up to Maitland from there. Much shorter, but you'll have to be confident of sticking to your path well. I live under the VFR lane and it is scary watching the occasional light plane going up the down lane or vice versa. Of course, if you aren't allowed to take your aircraft over built up areas, then it's Go West, Young Man.