We spent 8 days in the Eastern Townships recently for our summer vacation trip.
We day tripped all over the place! There is plenty of variety in day trip destinations and scenic drives in this large region of the province. Geographically the Eastern Townships is the part of Quebec along the Vermont USA border. Lots of nice hills and lakes and mountains and plenty of villages and small towns. There is a very good official eastern townships road map that has all roads (big, small, very small!). The Townships have three official driving circuits: The Wine Trail, the Townships Trail, and the far-eastern the Summit Trail. We bought a $3 book on the townships trail and it was totally a good idea.
You arrive in the Townships at the Granby exit of the Autoroute les Cantons de l'Est (aut 15) and the tourist office at this exit has good info as well as the official road map and the Townships Trail guidebook.
Here's some pics: