Ocosingo is a city in Chiapas.
There are urban colectivo's, but the city is small enough that it is best to walk. If you are coming from Comitan, you will get dropped off by the farmers market, which is also the point to catch a colectivo for the ruins. Ask directions for the central park to find most of the hotels, restaurants, atms etc.
For most, Ocosingo is only a jumping off point for Laguna Miramar or Toniná. However, if you do decide to stay here, the town feels friendly enough and is not a bad place to stay a night. The centre has a leafy colonial style plaza, and near the colectivo terminal is the "peasents" market, where local farmers come to sell their produce.
There are Automatic Teller Machines (ATM) in Ocosingo. Before heading into Laguna Miramar you should pull out any needed cash here.
There are a number of decent hotels off the main plaza that are priced between $15 and $30 USD. Budget travelers beware, at the time of writing, apparenlty there are no dormotories in town.