Basically an attempt to upgrade services for passengers. At the moment large city bus stations have websites.However there are exceptions, in Varna there are actually two bus stations 100 metres apart.You can get pretty good information online from the biggest the Central Bus station, but from the smaller one (the 'Young' Bus station) not much and, if you want to get to Burgas, this is the one you need. In Veliko Turnovo there are also two bus stations.However, in this case, they all serve similar destinations.
Certainly one tip about using the buses is that the bus toilets are never open so you will have to wait till it calls in at a bus station.Secondly whilst the buses are more expensive than the trains (unlike the UK for instance) they are much cleaner, more modern, there are always in flight movies; but they are subtitled in Bulgarian and since they presume no foreigner ever travels on the buses they turn the sound down so low that the English language dialogue is inaudible. However there is normally wifi.