Hi mate...
Is that our summer or yours? It makes a difference. Download the latest timetable from their website - the week between Xmas and New Year is about the best time to visit all year, due to the extensive services, but anytime is VERY enjoyable. Probably my second favourite line anywhere, after the C&TS. Belgrave is only just over an hour from central Melbourne on the electric commuter network, but there are places to stay closer if you wish - Belgrave, Upper Ferntree Gully or Box Hill will (and do) have motels etc Line is very friendly (or were last time I was there) G-43 is a beautiful Beyer garratt and you want to take the run to Gembrook - gives teh best of the scenery from the rainforest to the more open bush, and there is another great trestle besides the one at Belgrave
PB site There is not the insurance hang up you find in places either -
G-42 Belgrave trestle
All in all, a great place to visit - small engines, working hard, beautiful scenery - you cant help but have a good time...
(write to them well before your visit - introduce yourself and see if you can organise a look around - worked for me at the UP steam shops. If people know you are coming from overseas, they tend to be very helpful)
Cheers