Common Cause's voting helpline/hotline is 1-866-MY-VOTE-1; TrueMajority's voting helpline/hotline is 1-866-OUR-VOTE. Other nonpartisan groups also sponsor each of these lines. Any problems at all, call them. And there will be problems. Republicans already beat us up with the fear stick; if that doesn't work, what's left but intimidation and "incompetence"?
TrueMajority also has a three-prong "Election Preparedness Kit," whereas American Rights at Work provides a downloadable handout with which you can protect your voting rights, and another one which provides a list of voting violations to look out for while you're voting.
Step five of the first American Rights handout suggests something I didn't think of: if the polling place doubts your right to vote there, and offers a provisional ballot, you can try offering more ID in an effort to cast a regular ballot. A provisional ballot is better than nothing, but you shouldn't have to settle for that if you know you're in the right place.
Good luck and God bless.