Jeppesen charts list the transition altitude/level on them. In Europe, the first time you descent from a flight level to a QNH altitude, they'll give you the altimeter setting, just as they do in the States. (Here: level at FL190, "descend and maintain 15,000, Houston altimeter 30.05." There: level at FL80, "descend three thousand, Heathrow QNH 1015.")
I sat through "International Procedures" class at Continental several years ago. A lot of it was position plotting, how the NAT tracks work, entering and cross-checking your flight plan coordinates, use of HF radio and SELCAL, etc. Back then CO was flying mostly DC-10s across so ETOPS wasn't a big thing ... now with 757, 767, and 777 flights I'm sure ETOPS is covered at length. At the end the guy told us about some Customs "gotchas" ... ways to get yourself and your crew detained for quite a while by saying the wrong thing at the wrong time!