Selos-postais.com is an interesting site that is a must for collectors of Portuguese material. Postal historians, with an interest in this part of the Iberian Peninsula, will find much of interest in this site. Unfortunately the text is completely in Portuguese, which restricts many English speakers.

However, serious collectors should not be discouraged from looking at this site on language grounds.

Philatelic Database has a number of articles on Portugal and Colonies.