May I ask what it is you do that brings you to Amherst ? What do you like to do, I can point you in the right direction
All of the suggestions are good ones. I spend a lot of time wandering around the notch( Mt Holyoke & JA Skinner SP), take 116 south out of Amherst and the visitors center is located at the top of the hill. You can park and do about 6 miles in each direction before you cross a road.
Right below the Mt Holyoke summit house is my favorite bakery, Barstows dairy store and bakery, the M&M will lead you right by it. The summit house concerts are now being held at the Young Men's Club on east street in Hadley due to the deck at the summit house being "un safe" You can also find concerts on the common in South Hadley (116 @ Mt Holyoke College) Both are on Thursday nites.
Northampton has some great places to eat, Greenfield is getting its fair share of first class eateries too. Bueno E Sanyo is good Mesa Verde in Greenfield is better
In September 30,000 college students will appear in Amherst (pop ~34,000) that's its own spectacle when the population of the town doubles in a week. Check out eateries before this happens unless you like waiting and walking. If you park Illegally in Amherst you will get towed
If you need details about anything just let me know