For information about the island and accommodations, call Montecristo's two hostels or the local nonprofit CORDES (tel. 503/2235-8262 or 503/2883-4825; www.cordes.org.sv), which helps local families find work, and can arrange lodging, transportation, and tours.
The island has no shops other than a single tienda, so you'll need to head to San Salvador or Puerto La Libertad for things such as banks, hospitals, and Internet access.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.