Working for a new business is completely different from working for an established one. You know this, but many job candidates don't.

I used to give job applicants what my husband called my 'green beret' speech: If you don't think it's fun being scared all the time, staying awake worrying, not knowing from one day to the next what you'll be doing, then please go now. (It went on longer than that, but you get the gist.)

I developed this speech after one too many people had asked what kind of guarantee I could give that my new company would be successful. The answer, of course, was: none.

What I learned to value in the many great people I hired were a few standout qualities:

1. Interstitial Instincts

At a start-up, your needs change constantly. You never quite know what you're hiring for. So you have to find--and keep--people who are great at scanning the horizon, spotting a need, and filling it, whatever it is. They don't ask for work; they find it. This requires a lot of flexibility. People like this are worth their weight in gold. And they're also usually wildly underappreciated in traditional corporations.

2. Innate Mentors

You don't have time to nurture everyone, but everyone needs to feel that he or she matters. So you want people whose natural tendency is to look after those around them. You do not want people who are competitive for credit and need a lot of your attention.

3. Specific Experience

Although start-ups are often full of very young employees with little track record, I find that people who have deep knowledge of a skill or discipline are more valuable than enthusiastic neophytes. They bring expertise into the business, know what is needed, and do it. Youthful energy is great, but know-how moves a business forward.

4. Nerves of Steel

New businesses are scary. Most fail. Worrying about it doesn't help; solving problems does. You need people who don't frighten easily and who (within limits) enjoy the sense of knowing that every single thing they do makes a difference. That's the upside of fear.