A friend of mine is working on a startup, and she's non-technical (not retardedly non-technical...she used Linux on the desktop for many years, and has designed and built a number of very nice looking websites, but she's not a developer or an engineer by any stretch), so she'll be looking for an engineer. She asked me what she should be doing to insure she is able to attract a good technical co-founder.

Here's what I told her engineers look for:

Proof that they get shit done. This is the first thing you'd look for in an engineer for starting a company, and it's likewise the same thing you need in a business guy. The definition of what shit needs to get done is very different, but it's still the most important thing. So, what projects have they headed up and gotten done? "Business guys" need to wield the phone, email, project budget, underlings, teammates, etc. in order to make things happen. If they have excuses for why their team or their prior workplace was crappy and held them back, or whatever,
they might not have the right attitude.

Be willing to do the stuff that hackers hate. This usually includes business development, accounting, taxes, legal, etc. A lot of talking to people and choosing vendors and service providers, and figuring out ways to get everything cheaply but in a timely manner.

Decisiveness is probably important in a business guy. Not recklessness...just the ability to make decisions in a reasonable time. They need to be a good and quick judge of character, since they'll be making most of the deals...and a bad partner early on can spell the end of your startup.

Likewise, they need to be honest and have character, themselves. There are business guys who get ahead by screwing others, but you probably don't want to work with them (because they'll screw you, too), and unless they're really good at it, in the end it will backfire. The tech industry is, perhaps surprisingly, polite. Competitors are friendly with each other, and very rarely bite each other in anything other than honest ways...because a competitor one day is a partner the next, and the more you grow and expand your offerings, the more this will happen. For startups, a competitor one day may be an acquirer tomorrow, as well. So, don't work with people whose primary competitive philosophy is "screw everybody else". Competing aggressively is obviously mandatory. But, if they'll say anything to make a sale, it's not good for the long term life and growth of your business.

Bring money or the connections to get money. This is crass, of course, and there are lots of other useful things a business guy can bring to the table, but bringing money to the table is an indicator of almost everything else you're looking for in a business guy (either that, or dumb luck). It's probably not possible to have good money from a good investor on the table without a prototype...but if they can arrange a meeting with an angel two weeks later to show off your early stage prototype and get the wheels turning on raising a round, you might have a winner.

Be easy to work with, and willing to learn. In the first few months, there's not much to do besides "make something people want", so they need to be able to be a contributing partner on that task. Design, maybe. Docs, maybe. Getting feedback from potential customers, definitely. Figuring out the data you need to build the right things for the right customers. This one is brute force Googling and making phone calls. Finding out the size of the opportunity (and whether other opportunities could be addressed with the same technology), making an honest assessment of the competition and figuring out their weaknesses, etc.