Don't miss the White Mountains of NH or you will miss the most beautiful parts of NE. Drive to the top of Mt Washington, take a paddle wheel steamer on the big lake. If you do go in October, the White Mountians is one of 2 places in the world with the most vivid colors. Also has great food, great shopping, and is low cost. Start with this site.
http://www.visitwhitemountains.com/