Thank you for all the reply's, they all have good points
So here is my first draft 
1/ Held on private property. 
2/ 120 odd km from Melbourne.
3/ 2 x  loops graded green, blue, working on a black.
4/ All loops travelling in the same direction. 
5/ Small groups with a ride leader for assistance and info. 
6/ The longest loop should take around 20min to 30min  to complete.
7/ 1 set of practice hills which can be accessed from the green or blue loops.
    But not part of either loop.
8/ Riders can progress up the loop levels.
9/ Riders can swap ride leaders and do the same loop or do another loop  with 
    a different leader as everyone has their own way of look at the same things.
10/ BBQ  lunch  
This would be great!
I've just come back from Starglen Lodge and that would be a top venue for something like this. It has just about every type of terrain, rocks, loamy single trails, fire trails, hills, ruts etc.
I rate myself as maybe Level 1+. I had a ball at the place.  
