travel from paris to normandy

Train to Rouen, Caen,or Bayeux. Bayeux is not a bad starting point. The beach area is massive, about 50 miles long, so plan accordingly.

Adding to what Frank said, you cannot get by train to the D-Day Beaches from Bayeux or the other two cities/towns.

The train takes you from Paris to Caen;
a tour guide will pick you up at the Caen station
and take you to the Memorial of Caen, the D-day beaches, American cemetary, etc.

You may buy your tickets at linkparis.com or at
http://www.memorial-caen.fr/portail/index.php

Several trains daily from Paris (Gare St Lazare) station. Ssome are direct and some have a stop with a train change but r/t was only about 50$ the last time I checked www.bahn.de

Also don't worry about the best tour prices in Normandy. Book with Battlebus @ battlebus.fr and you will not ever regret a penny you pay them. Only good things to say on Battlebus on this helpline. They have several different tours available and all are explained on their web site. Book early as they stay busy. Bayeux is where you need to stay for Battlebus tours and is also one of the best places to see many invasion beaches, and other DDay highlights.

Ditto to what Tony said. Train from Paris to Bayeux for a few nights (we spent 4 nights), Battlebus Tours. Fabulous. Unforgettable.