You will need your passport to buy train tickets.
Consider travelling only in Sleeping wagon (First Class) or Kupe (Second Class) - that's the closest to comfortable travel, don't try to save money on lower classes - you'd regret it.
You can buy tickets at the Railway Ticket Office or through an agency with delivery. There are often queues and unpleasant staff at the Railway Ticket Office so spending a couple more Hryvnas on the agency is worth it.
During summer season, train tickets are sold out for long time ahead so plan and buy well in advance.
Your tickets will be checked when you get on the train and during the journey. You can purchase bedlinen from the conductor for about 20 UAH or bring a sleeping bag. There is a bar open usually until 11pm where you can purchase drinks and snacks, it is better however to bring your own. Also toilet paper and bottled water.
Central Rail Station
Vokzalna pl., Kiev
Train schedule and prices in Russian and Ukrainian language can be found on
www.uz.gov.ua or here
Central Ticket Office
T. Shevchenka 38/40, Kiev
(6-45 days before travel)
Ordering train tickets
poezda.net or hafas.de