If convenience and a cheap price are more important to you than a super-comfortable journey, travel by bus—but keep in mind that the quality of buses in India varies widely. The state-run Volvo buses are a good option for intercity travel. Some "tourist" buses end up picking up hitchhikers, so by the time you reach your destination people are sitting in the aisles and sometimes even on the roof. If you don't mind an adventure, or if you have no other choice, by all means take a bus. Otherwise, take a train or rent a car and driver. The easiest way to get a bus ticket in advance is not from the bus stations, but from many of the private vendors in tourist areas. Your hotel reception or concierge might be able to help (for a fee).