Essays / What are the "do's and dont's" of an introduction of an essay? [8]

Hi all,

I have a really exciting paper to write... (/sarcasim) on...
Define portfolio investing and describe what constitutes a well-diversified portfolio. Using examples, discuss some of the factors that might affect the management and performance of an investment portfolio.

Can anybody guide me to anything which is related to the "what not to do" section of the web? I'm completing a set of papers in the aim of becoming a certified financial adviser, so all papers are Commerce/Business/Finance related. My previous essay I didn't have too many issues with the opening paragraph, however this one I find myself saying "in this essay I will discuss etc etc". I always thought that that style of writing is a bit of a no no? It's effectively a 100 level paper, so no opinions can be of my own... I'm new to these forums, is there a thread somewhere already tha I could view?

Sorry, being kinda vague. Given this is an essay forum, I'm also a bit paranoid of my own post grammar...!!