How do I co-author my first paper? I am new to the world of academia and pursuing a Masters degree in HCI (Human Computer Interaction).  One of the goals I have set for myself is getting my first publication(s) before I graduate.  

Now, obviously, I'd like to work my way up to potentially being a first author but that seems a bit beyond me since I have never published before.  Therefore, I figure it might be easier to work with someone else and establish myself as a co-author.  

Now, how do I go about even finding someone who is working on a paper and approaching them asking if I can help them out to potentially being a co-author?  It seems like a very taboo subject and might be insulting to ask?  How do I go about doing this?  Any suggestions or advice is greatly appreciated.
You don't first co-author a paper, you first collaborate on a research effort. Then, if said research effort leads to interesting results, you co-author a paper. So you need to look for someone doing interesting research that you think you can contribute to. Talk to professors in your department and ask about the research they and their students are doing.

Of course, since co-authoring a paper is important to you, when you find the opportunity to be part of a research project you should ask the professor: "Do you think this is likely to lead to a paper before I graduate?" Nobody can promise you a paper (even if you do everything right, the nature of research is that we don't know everything in advance). But he/she will probably have some intuition about it. You should also ask what you specifically need to do to merit co-authorship credit on the paper that comes out of the research.