Hello, Melanie: I wasn't as adventurous as KS&HC. I hired Nahuat Tours to take me on an all-day tour of the Volcano Complex at Cerro Verde National Park + an excursion to Lake Coatapeque. Just Google them or look them up on TripAdvisor. The whole thing lasted about eight hours and I highly recommend this company. I had Mario Jr. for a guide and he is great. It's not cheap, I don't recall the exact price but it was well over $100, but that included the entrance fee to the National Park and the boat ride on the lake. Also, when I went there was only I and one other fellow on the tour, so it was basically a personal tour, not a big group of tourists. Anyways, whichever way you choose I'm sure you will love it. Let me know if you have any other questions.

I'd recommend renting a house online. Most of the properties are private houses. There are 2 Turicentros "tourist centers" but the only hotel is Torremolinos, and its not very well maintained, check out the reviews here on Tripadvisor. There is one hostel but I don't know anything about it. Hope that helps.

I don't know the cheapest way but can thoroughly recommend Nahuatours, in particular their excellent guide, Moisés for a full day tour. It includes Joya de Ceren, a Mayan village declared by UNESCO as world heritage in 1993 and considered the "Pompeii of America", the ceremonial center of San Andres ruins and the museum. Finishing with a visit to the archaeological park “Tazumal” which has the most impressive Mayan pyramid in El Salvador. Includes panoramic views of the beautiful Coatepeque Lake of volcanic origin and a visit to the historical center of Santa Ana.