I will be in Paris on June 2013 and would love to take a day trip to Bruge but do not know which train to take. Please advice. Should I book train before leaving San Antonio or do I have time to do it once I arrive in Paris?
You need to get a Thalys train from Paris to Brussels and then change for Bruges. You will be able to book tickets in Paris but it can be much cheaper to book online at www.thalys.com. Unfortunately the tickets go on sale three months in advance and the cheapest ones will probably have gone by now. The cheaper tickets are also strictly limited to a single train on the Paris-Brussels legs, so if you miss that one you will have to pay a full fare again.
Thalys has a direct train going to Bruges every evening, and a direct train back to Paris in the morning. All other times you will have to connect via Brussels. http://www.thalys.com
We booked a day trip from Paris to Bruge, through Gray Line Tours. They are at Gray Line Tours.com. They sub it out to another company in Paris. It was a good day trip and enough time, as far as we were concerned. It was a very long day though.