If you encounter a word you don't know, then use a dictionary (an English-English is recommended) to find the definition for each.
A good dictionary will also give you a sample sentence so you can see how the word is used in context.
Homework Sheet - Vocabulary ( This sheet (in PDF or Word format) can be used to write down new vocabulary and their definitions from the vocabulary exercises on this site, and students are encouraged to then write sample sentences for each word as a way of learning how to use the vocabulary in context.
A list of commonly-used vocabulary with a recording of the words in Real Media and Windows Media formats.
As you learn the vocabulary, try to use it in other situations.