We are traveling to Paris and Brussels in late November and are a little confused about the French train reservation policy. Do we need to reserve from Paris to Brussels and from Paris to the Normandy area? Are there other types of trains?
The primary fast train between Paris and Brussels is the Thalys train. This train does require a reservation. Whether or not there's an addtional fee depends if or if not you are using a Eurail pass. If you are not, you can buy the ticket online and the seat reservation will be included in the cost of the ticket. If you are using a Eurail pass, there is a "supplemental" or "reservation" fee. If your pass is at least a 2-country pass that includes France and Belgium, the fee is 26Euro. If it only includes one of the two countries, the fee is 44Euro. And, this is for 2nd class. For 1st class, the fees for the same descriptions above jumps to 41Euro and 69Euro.
CLICK HERE to see the Eurail web page on International Reservation Fees.
For the remainder of your journey into Normandy, you could be on more regional trains for which there is no additional fee. However, if you will be on a higher-speed TGV train, there will be a 3Euro reservation fee.
The only reason to buy a ticket in advanced for Thalys is that you can get a discount (sometimes). The downside is that it locks you into taking a specific train. At that time of year, you can usually show up to the station, buy your ticket, and get on the next train.
You can also take the slower route through Lilles on French and Belgian rail. No reservations required or possible.
To correct Tom, most if not all trains from Paris to Lille do require a reservation. The train from Lille to Brussels does not.