In Brazil, a useful compendium of city maps and main road networks is published by Guias Quatro Rodas http://guia4rodas.abril.com.br/, a Brazilian motoring organization, which also has guides to Rio, São Paulo and other cities, states and regions. These are easy to find in bookstores, newsagents and magazine stalls. Topographical and hiking maps are difficult to find, though very occasionally they are available from municipal tourist offices or national parks in Brazil.
A printable map that is up to date, you can find at http://www.transportes.gov.br/bit/mapas/mapas-print/estados/TO.htm
See an example below.
Garmin and Tomtom offer gps navigation including Tocantins and Palmas.