There is a site with abundant content for an absolutely fascinating introduction to the falls. Do not miss it. It is part of the Science Museum of Minnessota´s Greatest places and includes photos, virtual reality, postcards, erosion activities, location map, comparative data and more. Just great. http://www.sci.mus.mn.us/greatestplaces/book_pages/iguazu2.htm
Another one not to miss is Natural World Heritage´s full description of the Falls, declared a Natural World Heritage Site. http://www.wcmc.org.uk/protected_areas/data/wh/iguazu.html
Offical government site of the Province of Misiones http://www.misiones.gov.ar -
Hotels and other accommodation: www.misiones.gov.ar/turismo/hoteles.htm
Pictures of Misiones : www.misiones.org.ar/turismo
National University of Misiones : www.unam.edu.ar
http://www.corrientes.com.ar - Official site of the province of Corrientes
http://www.corrientesvirtual.com.ar/turismo/index.html A local site containing complete info of the area, including nature reserves and tourist areas.
A very good decription of the area under "Ibera", though this is a general site on tourism in Argentina. http://www.argentrip.com"