Scolty is good but is not easy to find your away around if you are doing anything other than the fireroads and some of the singletrack is quite technical. The Neep Route in the link below would probably be OK though.
http://www.mtbtrails.info/Default.aspx is a good resource, one ride that is quite scenic and not too hard is the Forest Trail at Cambus O’May about 5 miles west of Aboyne. You can add to it by riding around Loch Kinord – when you cross the road from the Burn O’Vat car park, turn right rather than left and that will take you round the Loch.
For a longer ride on the Saturday, to be honest there are better rides than the Fungle especially if it has been wet. If you are fit, Mount Keen is doable in 5 hours but for most would be longer. The Loch Muick to Glen Clova is a classic and easily doable in that time but doe involve some hike a bike. Clachnaben, south of Banchory is good but the descent does involve drainage channels.