We stayed at Posada Las Flores. 1a Avenida Poniente Norte #17 Centro Historico. It's alright for a night or two. it is cheap! See TripAdvisor
It's not far to walk from Cristobal Colón main bus station on Boulevard Drive on the main High Way. This is where you will also find mini buses Colectivos to the Frontier for Guatemala and to Cascada el Chiflon, Velo De Novia
There are 2 bus terminals for 2 different entrances to the lakes. Buses to Largo Montebello are from Calla 2a. Av. Poniente Sur 29
There are 2 tourist information offices, The state tourest office on the main plaza "Central Park" in a wooden box and the municipal tourest office just off the plaza, on Calle Central Norte (Dr. Belisario Domínguez)
Border crossing to Guatemala, (Ciudad Cuauhtemoc/La Mesilla) we took the mini bus at 5 am. Mx$50, passport control opens at 7 am. We did not have to pay to leave Mexico as we had arrived by plane. If you entered Mex by land or sea and stayed more then 7 days you will need to pay the new charge of Mx$325. We did get asked to pay 10Q each when we entered Guatemala.