As the granddaughter of a man who has a caboose in his back yard, I love trains. I wish there were more trains in the U.S. on which I could travel. I have made up for that by doing much train travel in Romania. In case you are in Romania in the near future, here’s how the system works:
Getting a Ticket
I always check the train schedule online before going to get a ticket (http://www.cfrcalatori.ro/index.php), though I suppose you could just go to the train station and ask too.
I have never had trouble getting a ticket the day of my trip, but if you want to be very sure you could go earlier. Sometimes you can get a discount if you get your ticket far enough ahead of your trip.
To get a ticket go to one of the ticket counters and ask for the appropriate ticket. Given my limited Romanian I write down the date, train number, time, and destination and hand that over. As far as I can tell the default for class is second class, so if you want to ride first class you would want to specify that too.
Finding Your Train
To find your train look at the large arrival and departures boards. The picture shows the ones in Cluj. Other train stations have electronic screens or smaller boards.
On the board you can either look for your train number (1742) or the final destination of your train (Bucharesti). Follow that across and, in the last column you see what line or track (lina) the train will come in on (3).
The line closest to the station is line 1 and you count out from there. In bigger stations there’s a tunnel that goes under the lines, so look for a staircase to go down if you’re beyond line 1. If you are not up for stairs there is usually a spot without a barrier between the lines toward the end of the station.
In some stations, like Cluj, you will find a sign above the line that says what train is coming next.
When the train pulls up you can double check the train number (IR 1824) and destination on the train. Some have the new electronic signs and some still go old school.
Finding Your Wagon and Seat
It’s now time to look at a ticket. In the second section you see the starting and ending cities (Cluj Napoca to Bucharesti Nord) and the times (leaving at 8:40, arriving at 20:41). In the next section is the date of travel (March 27), the train number (IR1824), the wagon (vagon 1), and class (Cls 2).
There are some important numbers here! You need to know what wagon you’re on and get on that wagon when the train arrives. The wagon number is on the outside of the train. The picture of the Bucharest train sign above shows wagon 2 (v. 2). When it’s the old school signs the wagon number is often written on the sign.
The final important number is the seat. This ticket is for seat (locuri) 56. You can go in either door in your wagon, but if you want to spend less time fighting your luggage down an aisle look for the seat locations on the outside of the train. In the above picture of the Sibiu-Medias train you can see Nr. Loc. 61-106. If your seat is between those, go in this door. If not, try the other door.
Once in the right wagon, look for your seat number above the seats. They are not necessarially in order so 32 may be next to 35, not 31 or 33 like you’d expect. I haven’t the faintest clue why that is.
The one exception is if you take a R train (regio)–formerly p trains (personal). There are no assigned seats on these trains, so just get on and find an empty seat.
The unwritten rule of seats is that if you have an assigned seat and someone is sitting in it you can kick them out (nicely, of course). But if you don’t particularly like the seat you are in, for example you are assigned to a cabin that is already almost full, you can generally find another seat somewhere and sit in it. You should stick to your class (2nd class if that’s what you paid for) and probably in your own wagon, but I have never had a conductor give me grief for being in the wrong seat.
At some point in your journey the conductor will come through to check your ticket. They will punch it and will likely leave you alone for the rest of the journey, though I always keep my ticket handy. Unlike other trains in Europe you do not need to scan or punch your ticket before getting on the train but you do need a ticket before you board. The conductor does not sell them.
Your Destination
Suceava Train Station-the sign was out of sight, had to ask
Other Interesting Bits
For those of you who haven’t ridden trains much (in other words, all you other Americans), there are a few things that are handy to know.
There is a trash receptical near your seat, normally under the table by the window. If it’s not there check under your seat.
There is also a spot to hang up your coat. Look for the little hook. Sometimes they hide behind the curtain.
There are curtains! If the sun is shining in your face or you just don’t like the scenery, you can pull them closed.
If the windows are not open and you are warm, don’t open them unless you are alone in your wagon or cabin. There is a belief here, particularly among the older folks, that moving air brings disease. If the windows are open and you hear someone making a fuss about ‘curent’ be prepared to swelter.
Good luck with the temperature in your wagon or cabin. I have been comfortable on a train. Occasionally. Wear layers. It might be hot, it might be cold, it might cycle between the two.
There are bathrooms on the trains, normally at each end of the wagon. Take toilet paper. A can of Lysol and a gas mask would sometimes come in hand as well. I have played bathroom bingo before–visiting one and deciding it was too disgusting before going to the other end or another wagon with the hope of better luck there. You may not want to subject yourself to too many bathroom visits, so drink sparingly.
Stow your luggage on the luggage rack above the seats or, depending on the type of car you are in, in the space between the backs of the seats.
The Romanian system is quite extensive so you can get a lot of places in the country by train. Enjoy!
Romanian Reflections 
When traveling by train I usually look at all the departures when I arrive, so that I know when I can go where.
Having but one experience on a Romanian train, it seemed quite straightforward. But that might have been because you both bought the tickets and were the tour guide. 🙂 Fun blog!
January 2013: I just came back from a journey involving Bucharest-Brazov by train. although the train was quite modern there was, as you point out, no toilet paper in ANY of the toilets, nor was there any water either. Our compartment was heated to tropical desert temperatures; the next was arctic. An added excitement to the journey was that the sliding doors to the outside opened and remained open during part of our journey.
That sounds about par for the course! Layers are your friend on a Romanian train–never know what temperature you are likely to get. Hope you enjoyed Basov and made it to Rasnov and Bran castle while you were there.