We would like some suggestions about taking a day trip to Bruges from Paris. How far is the train station from the town?
The train station is right next to the tourist center. Take the Thalys high-speed train train from Paris Nord station to Brussels-Midi. From Brussels to Bruges take a regular inter-city train; two per hour. For the Paris to Brussels segment it's essential book 90 days in advance to get the lowest fare. Head to http://www.thalys.com, tell the site you live and will be picking-up your tickets in France. You'll be able to print your ticket out at home.
If you can't find a good Thalys fare, there's an alternate route you could investigate. TGV from Paris Nord station to Lille, switching to a local train to Bruges. There's a short walk between train stations in Lille, but it's easy. You might need to buy discounted TGV tickets online and purchase your local train tickets once in Paris to get the lowest fare. Process for TGV is same as for Thalys. The Bruges train station is on the edge of town, and the few-minutes bus ride into the center will save you about 20 minutes of walking each way.
We used Gray Line tours, based here in the U.S. for our day trip from Paris to Bruges and back. You can book it on-line too.