The 126th Legislature, in the First Regular session, passed Chapter 270 of the Public Laws of 2013, establishing the apportionment of the Maine Senate, Maine House of Representatives and County Commissioner Districts. This public law was signed by the Governor on June 14, 2013, and will be in effect for candidates and voters participating in the June 10, 2014 Primary Election and November 4, 2014 General Election. There's much more information about the apportionment on the Secretary of State's website.
Until the new Legislature is sworn in on December 3, 2014, your Representative and your district number will be the same as it has been for the last 2 years. You can find your current Representative and Senator here - Find Your Legislator.
We will be adding more ways to find your new district over the summer, but for now, to find out what your district will be, please use maine.gov's Voter Information Lookup page (see image below). The first tab will tell you what your new district numbers will be, and the third tab will show you the candidates who will be on the ballot in your district. Once you have the district number, you can find contact information for House candidates here - 2014 Election Information.