Hi DS
First point I guess is when in the circuit, try to avoid using landmarks to time your turns - otherwise it's much harder when you're trying to land at a new airport! Your instructor will help you out on that - for instance, for a power-on approach I've been taught to keep going on downwind until the runway threshold is at about 45 degrees from the downwind track, then turn.
For landmarks, mostly comes from experience in the local area I guess. Google Earth is OK, and I use it to get a feel for the landscape.
For YLIL, the most useful landmarks are:
Mt Dandenong and the towers
Silvan Reservoir (just to the East of MtD)
Lilydale Lake (useful because due South of the airfield)
Power lines (about 2nm south of the field - very useful if you get lost)
Sugarloaf Reservoir (to the West, other side of mountains)
Yarra Glen (racecourse is a good landmark)
Steel's Hill (to the South East)
Coldstream Airport (but don't get too close!!)
The Melba Highway is good to remember when you're coming back from the training area - track just to the left of it, staying clear of YCEM and passing to the west of Coldstream township.
And the downwind leg for either 18 or 36 is just to the West of Victoria Road, another good landmark.
Cheers