Here is a helpful handout for developing your Research Question. Yours should still be fairly flexible at this point but as you get further in the organizing/writing phase it should solidify.
Here is the detailed rubric that IB will use to grade your essay. Consider this required reading so that you know where you are heading.
Here is a folder of sample Extended Essays from IB. Use them as guides/models for your own. Most of them have the scores included in them so you can see how they approach it.