Roswell is a city in New Mexico.
South towards Carlsbad and Fort Stockton (US-285)
From Pioneer Plaza on Main Street and between 4th and 5th Street take the Southbound Bus going the Airport. Get off on Relief Route and walk east to the junction with US-285. Bus ride costs $0.75.
North towards Santa Fe and Albuquerque (US-285) and Northeast towards Amarillo (US-70)
From Pecos Trails Bus Terminal located on Main Street and 6th Street take the Northbound Bus to Roswell Mall. It costs $0.75. You can ask drivers at Chisum Truck Stop further north or hitch at the junction even further north.
There are five bus lines in Roswell, though buses look more like some kind of ambulances. There is no info displayed on the bus, bus stops are hard to spot and there are no timetables and any other info on them. The best source of information is this website. Google Maps don't provide public transport for Roswell.