The Hook

An essay's "hook" is the first few sentences that serve to draw and inspire the reader to continue reading. This is something that usually serves as a place for "writer's block", but it doesn't have to be. Since this should be something that is the most interesting aspect of your unwritten essay, the best tip I have heard in constructing a good hook is to write the essay first. Seems like common sense, but it is definitely something that my REM 100 students do not take into account. Most of the students open with the original question that inspired them to write the essay in the first place. This tact is great except for one small detail, they open their essay with a question. Without getting into the actual merits of opening your essay with something like, "Have you ever imagined where a bra comes from?", I would like to explore some easy alternatives to the question "hook".
Try completing these sentences:

When I was thinking about this, I couldn't believe that______.

It was amazing to me that ________.

Imagine what it's like to_______.

The image I can't get out of my head is ______.

Taken from ehow.com "How to write a hook for an essay".

After writing the "hook", have someone else look it over and ask them, "after reading the first X sentences were you interested in reading more?". If the answer is yes, you have your "hook".

Serial Comma,,, 1,2, and 3?

The serial or oxford comma is the comma before "and" or "or" in a list of three or more items. I have always omitted this comma, but I have come to learn that this is largely a popular media (e.g., newspaper) thing. There is not written rule on weather or not to use one in a list, however, it has become the convention to use it to add consistency and clarity. Per usual, Grammar Gril has the final say,
"Consider this sentence: I went to see Zack, an officer and a gentleman.
Without the serial comma—I went to see Zack, an officer and a gentleman—it could mean that Zack is both an officer and a gentleman, or that I went to see three people: Zack, an unnamed officer, and an unnamed gentleman.
With the serial comma—I went to see Zack, an officer, and a gentleman—it could still mean two different things. It could mean I went to see three people (Zack, an unnamed officer, and an unnamed gentleman), or it could mean I went to see two people (Zack, who is an officer, and an unnamed gentleman)."

Bottom line, use it!

-Grammar Girl