http://www.ucc.vt.edu/stdysk/vocabula.html
Vocabulary: an ongoing process
This page offers hints for developing your vocabulary.

http://www.wordfocus.com/index.html
Focusing on Words
A rich source of information that will enhance your English-vocabulary skills! Experience the wonder of words by focusing on the Latin and Greek elements used in English. Visit this special index to the English vocabulary elements, groups and quizzes that are available for vocabulary learning.