I need help in filling out forms if I am a resident of Maine but work in Massachusetts

If you commute to MA each day from your home in ME you file in MA as a non-resident, and pay tax to MA based on the wages you earn working in MA. Then you file your resident ME tax return - it will ask you to report all income, and you calculate a preliminary tax on the full amount, but then you take a credit for taxes paid to other jurusdictions (namely MA). Result is that you don't get double taxed on your MA income. Hope this helps.