From limited research into NH law, it seems the only place where firearms are prohibited is a "courtroom or area used by a court." (15 seconds on Google.)

dben002 gives good advice. Your own state laws regarding firearms do not travel with you. There's a cell phone ap called CCW that gives a summary of various state concealed carry laws but still a good idea to do some additional research before you travel.

In Wyoming, carry is prohibited in "Any portion of an establishment licensed to dispense alcoholic liquor and malt beverages for consumption on the premises, which portion of the establishment is primarily devoted to that purpose."

So I can carry in the restaurant section of the local Applebee's, but can't legally go through the bar section to use the restroom. Stupid, but that's the law.