Hanmer Springs is an alpine spa town so it's a good idea to thrash your muscles there so you can really enjoy the hot pools! There are trails enough in Hanmer Forest to allow you to do that. They are not great trails but there's a good variety. Buy the mountain bike map from the i-site (information centre) in town and you'll be able to put together a very pleasant ride to suit your skill level.
There are several kilometres of easy trails south of Jollies Pass Road and more than 20 kilometres of intermediate and advanced trails north of the road. The place to start is at the Hanmer Forest entrance on Jollies Pass Road about a kilometre out of town. The park is very visitor friendly with signs at the entrance and every time a track branches. You won't get lost and you'll easily find your way back.
Easy Rider is an excellent easy 6.6km loop best ridden anticlockwise.
I quite liked this combination of intermediate and advanced trails: Upper Dog Stream, Big Foot, Jolliffe Saddle, Timberlands, Swoop and Swamp. Many trails in the park are hiking style trails and you won't find much of the fun stuff like berms, rollers, airs, drop-offs, and so on. But they are pleasant and they'll set you up for a relaxing spa!