One of the things that can be quite difficult when visiting a new place is figuring out where to take photos.
Since I am currently in a new place, I’m going to write down some of my thoughts while they are still fresh.
This is my advice for finding places to photograph once you arrive.  Preparing for the trip is an entirely different topic.
The easiest way to find out what areas of a new place can make a successful photograph is somewhat unexpected — look at postcards.  If the area you are visiting has any kind of tourism, there are likely postcards everywhere.  A local (or in the case of a National Park, ask the Ranger) or Hotel Receptionist should be able to tell you where the picture on a postcard was taken.  At the very least, it will give you a place to start.  Then buy a few postcards to thank the photographer (or buy them on the way out, after you’ve captured the photos you were after), and because postcards are a lot of fun.
The next method I use to find photos is to ask a receptionist, tourist information, or park ranger for advice.  Often the well known areas are a good place to start.  Famous buildings and parks are famous for a reason, and visiting the obvious places can act like a good warm up for the trip.  Notre Dame (Paris) has been photographed to death.  So I would visit it for your photo warm up day will help you get ready for the other things you will see on your trip.
Next person to ask is a local.  Bars can be great, especially if they speak your language.  You may also get lucky around the city if you look for other people with the big cameras.
Finally, just walk around, you never really know what you will find.  A few days ago I set off in a general direction in Helsinki, and ended up finding some amazing wild flowers by the side of the road.  It was not my intention to find them.  I made a wrong turn while heading to my target location.  But the initial results look great.
Hope you’ve enjoyed my thoughts.  Happy Shooting!  No photo this time since I’m in a hotel waiting for batteries to recharge.
-M