UTA Portuguese Exercises http://www.laits.utexas.edu/orkelm/ppe/intro.html
Strengthen your listening skills by hearing native speakers from different regions of Brazil talking about a variety of common themes. Includes transcripts of the audio in Portuguese and English.
Word Reference http://wordreference.com/
An outstanding, comprehensive dictionary for many languages, Portuguese included. Also includes the best forum on the web for discussing grammar and vocabulary. Highly recommended!
A site dedicated to the learning and study of foreign languages in the 21st century. Great resources and helpful hints from a man who speaks 8 languages fluently (including Portuguese). You can do it too!