We have developed a large number of markers for Amazonian species. The protocol is provided as a PDF and includes all steps from DNA extraction to testing of primers. There is also a version in Portuguese. You can cite the protocol directly, or cite:
Farias, I. P., Hrbek, T., Brinkmann, H., Sampaio, I. & Meyer, A. (2003). Characterization and isolation of DNA microsatellite primers for Arapaima gigas, an economically important but severely over-exploited fish species of the Amazon basin. Molecular Ecology Notes 3, 128-130. doi:10.1046/j.1471-8286.2003.00375.x
In this article, the protocol is described in broad terms.