There are a couple of options for matches but you'll likely have to drive a bit to get to them.
Steel Challenge shows one club in ME, in Frankfort (a little over 2 hours from you). I know nothing of the place, other than they are listed on SCSA's site, looks like a store though so you'll need to contact them about what they offer.
Tactical Attic
Frankfort, ME 04438
207 570 9018
http://www.tacticalattic.com
Other option is to head over to NH, either to Pioneer Sportsmen (
http://www.pioneersportsmen.org/) in Dunbarton, NH (about 2.5 hours) or at the Sig Academy (
http://www.sigsaueracademy.com/SiteMap/SpecialEvents.aspx) in Epping, NH (just under 2 hours).
Both places have a reputation for good matches.
Also about 2.5 hours from you is Harvard Sportsmen's Club (
http://www.harvardsportsmansclub.com/) in MA. Also a great place to shoot.
As far as suggestions go, if you've participated in IDPA before, you have everything you need, though you'll want 5 magazines if you can. You won't need the vest as drawing from concealment is not allowed. And bring plenty of ammo. Have fun and good luck.