Here are some Frequently Asked Questions concerning your papers. Part of the reason these questions are frequently asked is that different teachers have very different attitudes on many of these issues. Do not assume that others share my view.

1. Can I use the first person singular in my paper (I, me, etc.)? Yes, I do it all the time in my papers.
2. How should I make citations to the works I'm talking about? What's important is that you give me the page # you're referring to or quoting from. (In the case of Plato, give me the marginal number. In the case of Augustine, give me book.chapter.section.) You can put this right in the main text, in parentheses, or you can use endnotes or footnotes.
3. Do I have to have a bibliography? No. You definitely should give me the complete references for any sources you've found on your own. Also, just to get in the habit of being professional, you might want to give me the complete references even for the works we've used in class. But you don't have to put this information in the form of a bibliography. It could instead be included in footnotes or endnotes. What a complete reference includes will depend on what you're citing (a book, a journal, etc.). Different people give complete references in different ways, and I'm not at all picky about the details. Just look at how some other reputable work does it, and follow its lead.
4. What sorts of fonts and margins should I use? This doesn't really matter, within reason. But do double-space your paper, so I have room to write comments between lines. Also, number your pages. And don't waste a lot of time trying to make a three-page paper look like a five-page paper, by adjusting margins, fonts, etc. You're not the first to try this trick, and it doesn't work. (If anything, it creates a bad impression.) For the record, I think of one page as the equivalent of 250 words.
5. What if I can't make the paper as long as it should be? You'll know you've really begun to understand philosophy (and academics in general) when you begin to have the opposite problem: not being able to fit everything you need to say within the page limits. But it's perfectly normal, especially in a philosophy class, to think that you don't have much to say, certainly not more than a couple of pages worth. It's not a disaster if your paper's a little short. But that's a sign, usually, that you're not considering all sides of the question. So use your imagination, and consider what someone would say who's taking the opposite point of view from you. Imagine the possible objections. Write those objections down in your paper. Then answer those objections. Now you're on track toward a really good paper.
6. What if my paper is too long? It's no big deal if your paper is a little too long. I won't stop reading it! But don't be obnoxious about this. If I say I want eight pages, I won't look favorably on sixteen, no matter how brilliant they are, especially when I've been grading papers for six hours straight. Write the eight, then come tell me about the eight more you could have written. I'll be glad to hear about it.