Nang Rong is in no way itself a tourist destination, it is simply the nearest town to the Phanom Rung Historical Park and can therefore be a convenient place to stay for one wishing to visit Phanom Rung. That said, the fact that Nang Rong does not experience any tourism and is simply a perfectly normal Thai town makes it a interesting place to stay (for a short period of time) to experience the "real" Thailand.
The bus station has fairly frequent services to Bangkok's Mo Chit (northern) bus terminal. To the south Chantaburi is served by buses that travel via the border town of Aranyaprathet. The major towns of Southern Isaan-Buriram, Khorat, Si Saket, Surin and Ubon Ratchathani-are all connected to Nang Rong by bus.
The tuk-tuk and motorbike drivers who hang around the bus station are close to impossible to get a reasonable price out of. Fortunately, Nang Rong is small and if you know where you're going you can walk, importantly Honey Inn isn't that far. Even more fortunately, in the bus station there are several boards that give information about the town and the region, one of these boards has a plan of the town with accommodation marked.
A discounted ticket can be bought for both sites for 150 baht.
Rent a motorbike at Honey Inn and go for a country drive. The roads are in excellent condition. The drive up the hill to the temple has some brilliant viewing points. Isaan is poor an largely neglected by tourists, so take a diversion through the countryside and see rural Thailand. Arrange an early start and head out at dawn to avoid the scorching sun and tourist buses. Free maps and directions (enough to get you to the temples) are available at Honey Inn.
Rent a bicycle or motorbike at P.California guesthouse. The owner can give you good advice too. He is an experienced bicycle traveller.
There's not much, but there is a 7-11.
There's a smattering of cheap, pleasant, nondescript eateries. You won't starve.
For vegetarians there is a vegetarian raan ahaan (eatery / cheap restaurant) next to Kasikorn bank, next to a Chinese temple. They close early (5-6PM).