You must cite your source of information any time you use another person’s ideas, opinion or theory. You must also provide citations for any facts, statistics, graphs, or drawings that are not common knowledge. Quotations of another person's actual spoken or written word and paraphrases of another person's spoken or written words must also be cited.
This might be a good link, too: http://www.bbc.co.uk/languages/spanish/
Some of the other links no longer exist. I might suggest the Smithsonian Latino Center as a main link, as well as their list of Museums: http://latino.si.edu/collections/collections_LatinoMuseumResources.htm