1. General Service List (GSL):   http://jbauman.com/gsl.html

The GSL is a list of 2284 words that appear most frequently in texts. Experts recommend that students know all these basic words first before learning the more difficult words from the Academic Word List (AWL).

2. Academic Word List (AWL): http://www.academicvocabularyexercises.com

The AWL contains words that occur in academic texts. You should focus on the words in the first sublist (most frequent), then sublist 2 (the next most frequent), etc. 

3. Exercises for the AWL:  http://www.academicvocabularyexercises.com/id21.htm

There are many exercises here for the different sections of each sublist. You should start at the beginning with the first one and once you have mastered one set, move on to the next. The words in Sublist 1, for example, are more frequently used in academic texts than the words in Sublist 2, etc. There are 6 groups of exercises within each sublist.

4. Paul Nation: Levels Tests Online http://www.er.uqam.ca/nobel/r21270/levels/