Online guide for students who have to write an EE
I would like to suggest a site with instructions for writing essay, titled as Guide to writing a basic essay http://lklivingston.tripod.com/essay/topic.html
There are some differences towards writing Extended essay, but still this site may be useful. In the EE we would have to follow the research question, not thesis as suggested in the Guide to writing a basic essay, but most of the other things remain the same. Check the navigation on the left specially the themes: Outline, Thesis, Body, Introduction, Conclusion.
Really think that this site may help a lot.