@kacieaurore,
Maine and New England are not known for being good fossil areas. Most of the land has been scraped up pretty good by glaciers and there isn't much sedimentary formation up here.
However, I believe there are some dinosaur footprints in mid-massachusetts somewhere.
Most fossils (from anywhere) don't sell for very much unless you find something in extremely good condition or extremely rare.
I used to find fossilized sharks teeth in New Jersey and they were in very good condition, but I bet none of them were worth more than a few cents per tooth.
You can get some price ideas from this site:
http://www.paleodirect.com . But notice how nice their specimens are though. I've never found anything that nice.