Market Insider has comprehensive information for MA. schools including student / teacher ratios, locations, parent ratings, and more to help you in your choices. You can find it here > http://www.westernmasshomesforsale.com/mischool/zip/01002/
Good luck in your search and I hope this helps.
I would call the school district at (413) 362-1810 or check out their website http://www.arps.org. I know it depends on how many openings there are in each grade. Once one child is in, I think all subsequent kids automatically get in too. Please feel free to call or email me with any other questions or if you want to see any homes in Belchertown. I live here myself and love it!
Jones Group Realtors