Edit - many apologies to anyone that feels that this discussion was a waste of time.  

I just ran across an article (http://techno-anthropology.blogspot.com/2011/04/rough-guide-to-social-skills-for.html) on Hacker News that gives the barest minimum of a guide for social interaction. Unfortunately this isn't the high-quality advice you need to really handle social situations, though it will help with a few of the worst problems.

A few other rules that will help:

• Don't intrude on a conversation no matter how stupid or incorrect the arguments on either side are. No matter how you try, you will have turned your attempt to help into an intrusion into their social territory, and they will respond aggressively.
• Don't assume that being smart is the same thing as social authority; seeing that people are going the wrong way and telling them won't work. This is really social territory again, you're trying to take leadership.
• Don't assume that people equate brilliance and desirability. Don't even assume that people can tell that you're brilliant after talking to you for a while. Even if they do, they may not value brilliance.
• Learn to listen to people. Conversations have a natural pause inserted between concepts that is an opportunity for the other person to respond. Do not talk over anyone, instead wait for that pause. Try to stay on the same topic as the previous speaker, or a related topic. Avoid jumping back more than one previous topic without explicitly saying something like "I had a few more questions about <topic>," unless they do it first in the same conversation.
• To have a conversation with someone, ask them about their interests and when you find one that doesn't bore you talk about that. Try very hard not to talk about yourself unless they specifically ask first, and try to focus on what they have to say instead of what you have to say. If you are successful, they will give you opportunities to talk about your insights naturally. Avoid direct challenges; if you disagree then ask a question that exposes a hole, or say "it seems to me that ..."
• Conversations share a volume, and speaking at the same volume as someone else is a signal to them that you are part of their conversation.
• Avoid completing other people's words or sentences for them to speed up the conversation.
• If people don't laugh at your joke, don't explain it. Just continue the conversation. Don't be afraid to smile to show you find it funny, but always wait for someone else to laugh at your joke before you join in.
• To become friends with someone, you must have common interests and you must focus on those interests while you're with them. Do not assume that just because someone shares one of your interests that they will share others.
• Most people are not broken, though they are subject to biases. If someone comes to a different conclusion than you do, it probably is not 'stupidity' so much as you seeing a benefit or cost that they do not, or you valuing the benefit or cost differently. This can go both ways; sometimes even someone very shortsighted can have a flash of insight. The only way to know for sure is to ask them about it.

On the physical side:

• If you have not showered or bathed with soap in the last 24 hours and used deodorant, people will notice. If they do, they will almost never tell you. The same holds true for possible bad breath. The same holds true for clothing: avoid using a shirt two days in a row, change underwear and socks daily, while pants might be able to be reused for up to 5 days if they are not dirty.
• Do not approach within arm's reach (fingertips ourstretched) without them facing you. This is the approximate 'personal space' boundary. As soon as they back up even slightly, stop; you've gotten too close to them. If you find someone constantly edging away from you, adjust that distance upwards.
• If there is no space large enough to accommodate you around the person you wish to talk to, then wait for one or more people to leave first. When calculating this space, assume that each person is as big as their personal space, even if those spaces seem to be overlapping.

This is a long list, and it isn't even close to complete.

I'm linking to http://lesswrong.com/lw/372/defecting_by_accident_a_flaw_common_to_analytical/ at the suggestion of David Gerard.  It has a lot of deeper discussion into why this is worth knowing.