The unremarkable town of Xpujil (shpu-heel) is a good base for exploring the area's many ruins, and offers a few hotels, some unexceptional eateries, two ATMs (one at supermarket Willy's), an exchange house (Elektra Dinero on Calle Chicanna near Xnantun), an internet cafe and a bus terminal. Most services are along the seven-block main drag, Av Calakmul (aka Hwy 186). There are three gas stations in the area.
You can also stay in the village of Zoh-Laguna (population 1500), 9.5km north along the Hopelchén road. It's much more peaceful than Xpujil, but has only two simple places to stay and hardly any services; it's best reached with your own vehicle (taxis from Xpujil are M$40 to M$50). There's a small museum on the same block as Cabañas El Viajero; look for the lime-green building. Strangely enough, it's also a pizzeria with internet service.