Cynical but True
These are some conclusions that I reached during my three months of looking for a job. I interviewed at seven companies, which I will not name here. My comments only apply to technical positions at computer companies; I know nothing at all about other kinds of jobs and companies. And, what I say here applies to me, I think; whether it will apply to you is something I don't know.
So, without further ado, here the guidelines.
Personal Contacts are Critical
The first step is to get invited to a company for an interview. Most companies have a "careers" section on their website where you can send them resumes. In my experience, the vast majority of companies don't respond to resumes submitted this way (there are some notable exceptions though). What you need is for someone at the company to personally recommend you to a manager/recruiter.
However, getting such recommendations is not too difficult. All you need is a couple of friends in the industry: they, in turn, will know other people in other companies, and these other people will typically be more than happy to recommend you on the basis of their friends' endorsement. They do this because people are usually helpful, of course, but also because if you get hired they get a bonus from the company.
Keep in mind that even with an employee recommendation, not all companies will get in touch, so you need to spread the net wider than you think.
Nobody Cares About the Truth
At most of your interviews, you will be asked how interested you are in what the company/group does. Do not tell them that you have never paid attention to exactly that slice of the world that they deal with, but that you think it could be interesting, and that you like to try out new things. If you say this, you won't get the job (yes, I was stupid enough to say such things).
Now, I'm certainly not saying that you should lie about verifiable, objective facts. You should never do that. But, when it comes to questions of your interests and what you want to be doing, come up with a good story about how what the company does is exactly what you have thought about doing for ever, and how this would be the perfect job for you. This isn't too difficult—you can usually find similarities between your real interests and/or what you have been engaged in so far and what the company does. Trot out a few issues you have thought about that are relevant to the job profile, and talk about them passionately.
In the end, accept the offer where the things you said were closest to being really true. Do not feel guily about not telling the complete truth: you did not invent this game. They are forcing you to do things this way. This is all their fault. Think about George Bernard Shaw when doing this. He said, in an appendix to his play Man and Superman, "The man who listens to Reason is lost: Reason enslaves all whose minds are not strong enough to master her."
Interviewers are not Your Equals
Before you start interviewing, people will advise you, "Think of the interview as a conversation." That is good advice in general. The final answers aren't the critical thing; what is important is your overall interaction/conversation with the interviewer. However, be careful: do not think of the interview as a normal conversation with a colleague. Keep in mind that you are not equals.
In particular, you may run into a somewhat stupid interviewer. Unless you are careful, your irritation with how slowly the interviewer is following your statements will affect your behavior. You might come across as being arrogant. You might run into an interviewer who forces you to spell out a lot of very straightforward stuff in more detail than is useful. Don't interrupt the interviewer in an attempt to cut out the random details and get directly to the conclusion. Later the interviewer will claim that you were interrupting him all the time, and even shouted at him once or twice (these were the times when you weren't able to keep yourself from saying things that were *really* obvious).
So to recap, yes, think of the interview as a conversation. But, think of it as a conversation with an oversensitive but powerful being. Seeming excessively polite and timid is better than seeming rude and/or arrogant. Also, even if you are the type who doesn't feel intimidated by the interview process, interviewers will extrapolate even the smallest apparent abrasiveness to conclude that in a non-intimidating situation you will be even worse.
Clothes are more Important than You Think
Finally, although everyone likes to believe that they make decisions in a logical, rational way, that is not really the case. How much the interviewer likes you is determined to a large extent by incidental factors like what you look like & how you talk. This is all subconscious—if you actually try to convince someone of this (particularly people in the computer industry, who have an exaggerated sense of being logical)—you will only receive incredulous denials.
Unfortunately, I have very little advice to offer in this regard. I can't simply say you should dress formally, or informally. What works better for you probably depends on you. I can tell you that in my case there was perfect corelation between what I wore and whether I got an offer. So, if you have a string of interviews where you don't get an offer, you might try to change what you are wearing.