Okay, I get on the train with my luggage. What do I do with it? Where can it go? How much? Options?
Most of the trains have luggage storage areas at the end of each car for large pieces (watch them or lock them so no one takes them). There is usually plenty of room between the backs of the seats for 22" and smaller bags to slide down right on the floor and out of the way. Then there are racks above for small carryons - I just wouldn't sit under anything heavy - it was amazing to me that some people try to put really large bags up there.... Last year we were also on a couple of trains that were packed and we put our bags between our legs - many people just had them in the aisles too... In other words, you will figure it out when you get there. Have fun!
I use the luggage sections at the end of the carriages as I am not a light packer, and put my hand luggage in the rack above my head so I can see it. Anything of real valuable stays with me in my purse or pocket. I took a train from Genoa to Milan a couple of years ago and the train was full and didn't have luggage bays at the end of the carriages. The people in our carriage had used all the rack space and so we left our luggage in the corridor as it was the only space available. An inspector got on and threw a wobbly about it, carrying on in Italian to me, none of which I understood. I just smiled, pointed to the full racks and gave a very Italian shrug of the shoulders shaking my head. He gave me a long stare and then gave up and walked off.