Vocabulary

Academic word list:

http://www.victoria.ac.nz/lals/staff/averil-coxhead/awl/headwords.html (Headwords and sublists)
http://www.uefap.com/vocab/select/awl.htm (Headwords, sublists , definitions)
http://elc.polyu.edu.hk/CiLL/eap/wordlists.htm (Headwords, definitions, example sentences, pronunciation)


Glossaries:

http://esl.about.com/od/businessvocabulary/English_Vocabulary_for_Business_and_English_for_Special_Purposes.htm

Vocabulary exercises:

http://www.nottingham.ac.uk/~alzsh3/acvocab/index.htm (highlighter and gapfinder based on the AWL)
http://www.academicvocabularyexercises.com/id17.htm (Gapfil exercises organised by sublist)
http://www.uefap.com/vocab/vocfram.htm
http://uvt.ust.hk/about.html (Multiple choice exercises based on key academic vocabulary)
http://ec.hku.hk/vocabulary/tutorial/tutorial_list.asp?subject=English&subject_ID=1&sub_subject_ID=1&sub_subject=Business_and_Economics (This site has excellent games)

Dictionaries:

http://www.lexicool.com/ . (directory of the online bilingual and multilingual dictionaries and glossaries for speakers of English as an additional language)
http://www.thefreedictionary.com/commerce
http://www.oup.com/oald-bin/web_getald7index1a.pl
http://www.yourdictionary.com/