Having not done any tourist related stuff in Serbia I can only comment on getting around the place. The railway system is not the best at all with trains traveling at a slow pace, certainly south of Nis towards Macedonia and even north from Lapovo towards Belgrade; where trains seem to lose almost an hour getting into the capital. That said though, there are plenty of international trains and the transport options in Beograd are excellent; if not really well advertised. Maps are available from the tourist office at Beograd station though.
Zeleznice Srbije (ZS) operate the national rail service, throughout Serbia; also offering many cross border trains into neighbouring countries. You can plan your trip online using the ZS online timetable. While Beograd area timetables can be downloaded online, it seems that they can’t be from the ZS website.
A comprehensive list of both passenger and freight operators in Serbia can be found on the helpful Railfan Europe website’s Serbia page.
Train times and Tickets
Booking tickets for travel within Serbia can be done at most ZS stations. If you only require reservations for either Interrail, Eurail or railway staff passes then this can be done via phone to the DB office in London.
On some occasions the DB office in London can’t access the system to allow them to book reservations in advance but if you require reservations on the Beograd to Bar trains in either direction, or any other train involving Beograd, then travel agent Wasteels at Beograd can do your reservations. The very helpful Mr Popovic met us at Beograd station 30 minutes before the departure of our train and handed us our tickets in person. Contact Wasteels at: firstname.lastname@example.org
If choosing to use an Interrail pass, either for just within Serbia, or to pass through Serbia, all the relevant details on the passes, including the different types/lengths of validity available, can be found on the InterRail website.
Finally travel in Europe can be made a lot simpler by using the very, very, helpful smartphone app courtesy of Eurail. This app is available both online and offline and is always up to date (well it has been for the countries I’ve used it in; including for any planned engineering works); for me it was an essential part of my travel in Europe. This app is linked to the Hafas system, which countries like Germany, Austria & Switzerland use for their train planning online tool. Eurail has done what the individual countries haven’t though and made it available offline.
For the Rail Enthusiast
A comprehensive list of Serbian Locomotives by their respective railway system can be found on the Railfaneurope website’s Serbia page. This also explains a bit the various operators of the network and how they have amalgamated over the years.
Detailed maps of the Beograd area, including the integrated transport systems are available courtesy of Belgrade Maps and linked on the ZS website; these can also be sought from the tourist information office at Beograd station. A detailed map/atlas of the South East Europe & Turkey Railway Systems, which includes Serbia, is available from European Railway Atlas.