One of the biggest mistakes you can make going into an interview is thinking you'll do well because you're perfect for the job.

Everyone who got an interview is a potential perfect fit for the job. That's how they got through the resume screen. The interview is about something else: how you think, how you solve problems, how you react under pressure. And you are never quite sure of the quality the interviewer will focus on until you get a few questions.

Until now. Now Glassdoor has launched an interview resource where you can report what sorts of questions you got from a given employer. This is a great moment in altruism, really, because you are helping other people to get a job without knowing how doing so will help you. So I like Glassdoor's new idea right away, because of that. Because the very being of this tool assumes that people want to help each other.

I've sifted through lots of the questions and the first thing I noticed was that 90% of them are the kind you can study for. That's because they are all versions of common questions, just like those I see in books that list the 200 most common interview questions (here’s one). And, as always, you might think your interview will be a special case but it won’t be. You can learn the right answer for each question and just tailor it to your own career.

You can also learn from Glassdoor what sort of interview a given company favors. There is a tag cloud on the interview home page that is a laundry list of interview genres: behavioral, brain teaser, technical, and so on. For example, Microsoft is renowned for brain teasers (here's a book to study for those) and Deloitte is known for behavioral interviews (yes, you can study for that, too).

It's fun to read some of the odd questions people get. For example, a question during an interview for a video journalist at Turner Broadcasting was, “Who is the Minority Whip?” And a question for an interview for a flight attendant at Southwest Airlines was,

“You have 1 seat left on a flight, and you have 5 passengers waiting on standby, a military man in uniform, a pregnant woman, a woman and her infant child, an elite customer (one who is a frequent flyer of SWA), and a gentleman trying to go see his ill sister. Who will be the one to get the empty seat on the flight, and why?”

(Answer: At Southwest, elite fliers get preference unless it's life or death.)

The other information people can share at Glassdoor is which companies have nightmare interviews. Which is not the same as which company has difficult interviews. For example, according to reports at Glassdoor, Amazon and McKinsey are difficult, but not a bad experience. Google is difficult, too, and also it’s an unpleasant experience.

With all this data, Glassdoor will be the harbinger for which companies are bad to work for. Based on the interview process. Because Google is, right now, notorious for being a bad place to work. (Note: I can’t find a good link. But people I know in the know tell me this is true all the time. Maybe someone will provide a link in the comments section.)

I think the biggest problem with Glassdoor is that it's not fun. People are very serious in these reports. So you might not be able to get that interview information other places, but if you want to read about the worst places to work, peppered with spice and snark, try the Consumerist. They did a final-four style playoff, with match-ups like Comcast vs Bank of America, and readers got to vote. While it's too late to vote for the winner (AIG, is officially the worst company to work for) it's not too late to vote for how the trophy should be delivered.

In either case, though — Glassdoor or Consumerist — both are fresh foils for the BS lists that pop up every year about the best companies to work for.