Thinking of doing a trip from Mass to the Arctic circle with my Liberty next summer. Where is the best place to get topo map. maps?  I would like to do this trip with map and compass. What is the best way to plan for a expedition? 

It's impossible unless you travel (drive) to Alaska. I believe nothernmost point reachable by car is somewhere about 54 degrees north which is far shy of 66 for Arctic Circle.