Forming citations is the most tedious part about writing a research paper. Even professional writers dread having to deal with documenting their sources (and some of them even do it wrong.) The rules for citations are constantly changing and different teachers sometimes have different expectations. The best advice is to pay attention to the changes. The Modern Language Association is always updating the rules based on new technology and academic preferences.
One of the great new changes is that you no longer have to cite website links in your bibliography. This is awesome for students because it saves a lot of time when trying to format a bibliography since you no longer have to struggle with crazy hyperlinks and odd formatting.
I would definitely recommend buying the most recent version of the MLA Handbook. You will be surprised how often you actually use this. Most websites are not completely up to date with citation information so you end up with a lot of confusing information. Using the MLA Handbook means that you always know exactly what is expected of you, and you might even be able to teach your professors a thing or two about the new rules!