HOw do you book train tickets?
The train I was referring to is offered by Intercity company, so you can buy it via internet (you have to first register on their site): bilet.intercity.pl/irez/
but... I'm sure it works if you have Polish identity card... not sure how it will work with foreign one..
anyway, if it will be to overwhelming task you can try those people: flyaway.pl/content/english.html
I'm using them for booking bussiness trips, and they are fine. I don't know what is the fee though, because it is some general arrangement with company I work for. No idea if they work for individual people and at what cost. Ask them via email: koleje@flyaway.pl
Anyway buying at the station is the last and rare option I'm using...