Well, your textbook would likely be the best source of information on the subject, but if I were writing a two page paper on communication between close friends I would concentrate on contrasting/comparing and giving examples.
How is communicating with a close friend different than with others? Generally, we can categorize our relationships into three categories:
1). Acquaintances -- These are the people that we have the least investment in. Our relationship is situational and is a notch up from "stranger." We know the person's name, but our communication is limited to what we'd call "small talk." Personal information is not generally discussed and our conversation is limited mostly to factual information. We do not disclose any information to them that we deem "risky" and that could be used against us in some way. Our statements are generally "I" ones that focus on our needs. An example might be the person who serves you coffee every morning in a cafe. You know his/her name and can shoot the breeze a bit, but if the person quits and you never see them again you aren't particularly bothered.
2) Friends -- These are people that we have an investment in. There is a requirement for more disclosure. We begin to share biographical information, original ideas, and feelings with the person. We begin to use more "you" statements that focus on the other person. We begin to provide verbal support. We reveal information that is considered "higher risk" because a level of trust has been achieved.
3) Close Friends (intimates) -- These are our "best friends," the ones we have the greatest level of trust in. We will communicate information to these people even that could be used to harm us. Our statements are going to be more "feeling" based and less "factual" than in other relationships. Our guard will be down and we are more likely to engage in truly spontaneous speaking. We become better listeners with our close friends, trying harder to be effective. A higher level of slang and "inside jokes" will be used, and because of the relationship, more conversation that is "historically based" and wouldn't make sense to an outsider.
If I had to work on a paper regarding the subject, I would think of examples from each of these categories to show the differences. Though the subject is actually verbal communication between close friends, you can go a long way toward defining it by showing examples of contrasting styles such as the acquaintance and friend.