I did undergrad in Amherst and stayed in the area for two years afterwards.
If you can swing it, I would definitely recommend buying rather than renting. Rentals in the best areas of the Pioneer Valley (the Amherst area) run fairly high for being out in the boonies.
All the best restaurants and shops (and nightlife) is in Northampton. There are some really adorable neighborhoods right near downtown but out of the hustle and bustle (and plenty have fenced in yards). There is a bike path that allows you to get through Northampton very well. I would check out the northern part of State St, Perkins Ave, Prospect St, Finn St, and Summer St area. This is walkable/bikable to all the best of NoHo.
