Eddieg24 - Often, when we have been in an unfamiliar place we stop and speak with the local constabulary. As long as you are not in a third world country they will usually steer you along to to a reliable driver/guide who speaks your native language!
In Cherbourg Americans are treated very well-You might not want to leave-It's a great city!!
My suggestion-Ask a Gendarme for help/assistance! Be sure to set the fare with your guide in advance, try to avoid paying in advance, check to ensure you have the proper currency in an amount sufficient to pay and tip generously!
You'll have a blast!