What's almost as important as your resume and cover letter, and much more likely to slip your mind during the job search process? A good list of references. (Note that these should be separate from your resume; no need to waste space on that old resume cliché, "References available upon request.")
Who Not to Ask for a Reference
The challenge, of course, is whom to include on your reference list – and just as crucially, whom to leave out.
The following folks should never, ever appear on your list:
1. Anyone you haven't spoken to, and specifically asked to be a reference.
It should go without saying, but even if you're reasonably sure your former colleague or professor would give you a glowing recommendation, you should ask first, for several reasons.
First of all, it's just polite. If you're like most people, you probably don't love being surprised with phone calls and emails, asking you for things you weren't expecting. Even if you yourself are a raving extrovert and can speak extemporaneously on any topic, recognize that your potential references might not be the same way.
Regardless, you're asking for their time, and that's valuable. Do them the courtesy of giving them a chance to tell you if they can spare a few minutes right now to help you out.
Second, your recommendation will be better, if the recommender knows more about the job for which you're interviewing. Giving a heads up – and a little background info – gives your connection time to think about which aspects of your skillset and experience are most important for this new role, and allows them a chance to prepare some thoughts to share with your interviewer.
Third, there's a possibility that this person won't be allowed to give you a reference – or at least, a detailed enough recommendation to count. HR policies vary from company to company, but some employers are strict about how much information a manager, for example, is allowed to give about a former report. Don't assume that you know the policy ahead of time.
Finally, there's always the chance that your assessment of the relationship is flat-out wrong. The worst time to find out that someone wouldn't recommend your work is after they've told a hiring manager that they wouldn't hire you again under any circumstances.
Don't sandbag yourself.
An additional note: how you ask matters, as well. Don't just ask if the person will give you a reference. Ask, "Do you think you know my work well enough to provide me with a reference?" or similar. That way, you'll get a sense of what you can expect this person to say.
2. People who might say something negative ... or even less than positive.
Obviously, you wouldn't intentionally ask someone to be a reference for you, if you thought they'd say something bad about your work. That's why it's important to check in and see if they feel comfortable providing a reference for you, ahead of time – hopefully, you'll get a sense as to what they might say.
Keep in mind, however, that damnation by faint praise is also very possible during the reference process. The hiring managers will assume that anyone you ask to give you a recommendation is among your biggest fans. If they get a resounding "meh" as a response, they might think that this was the best you could do. Not good.
3. Anyone who doesn't communicate well.
This might sound judgmental, but now's not the time to lean on your connections who mean well, but don't speak (or write) well. Remember that your network reflects on you, especially when they're praising your work. If they don't seem on top of things themselves, they won't be able to impress a hiring manager on your behalf. What good is a recommendation, if it comes from someone the employer wouldn't hire?
4. Your current boss, except under very specific circumstances.
This is another potentially obvious one, but it's worth saying, anyway. Unless you're looking at a layoff, or your job is short-term – in short, unless your boss knows you're leaving, and is OK with it – don't ask him or her for a reference.
5. People you don't respect.
Whenever you consider asking someone for a reference, ask yourself, "Would I provide a reference for this person, in return?" If you can't honestly and wholeheartedly say yes, move on to the next connection on your list. At best, it's unfair to ask for something you wouldn't reciprocate; at worst, it might be your gut instincts telling you that this colleague isn't in your corner. Either way, just say no.