"Literatura de cordel" (string literature) are pamphlets or booklets that hang from a piece of string (cordel) in the places where they are sold. These are long, narrative poems with woodcut illustrations on the cover, often done by the poet himself. There are traditional themes (romances, fantastic stories, animal fables, religious traditions) and themes based on current events, famous people, life in the cities, etc. Cordel can be hilarious and very racy, too.
The largest concentration of this type of popular literature is in northeastern Brazil. We have a few works by the most famous cordel poets, J. Borges (José Francisco Borges, 81-3728-0364 or 81-9937-3838). Fortunately, his booklets are still widely available in markets; prices vary, but most cost less than fifty cents. I bought this one from a lady in one of the crafts markets of Maceió, Alagoas, and she let me take a couple of pictures of her stall with several bestsellers for sale.
In Rio, you can find cordel at the traditional feira de São Cristóvão and at the Academia Brasileira de Literatura de Cordel, at Rua Leopoldo Fróes, 37, Santa Teresa (they also sell the woodcuts).