For initial sales the easiest approach is to pitch to people you know who work at companies that might be interested in your product and convince them to act as an intermediately in getting you a meeting with the person who can make the buying decision.
I'd also recommend reading "Crossing the chasm" as it'll help you decide who the best companies to target initially are.
If your product is one that sells itself (i.e. it solves an obvious problem, clearly enhances revenues or reduces cost) then cold-calling might well work as well. Use networks like LinkedIn to find the appropriate people to pitch to and just send them an email or give them a call.
On hiring, we are only now beginning to hire direct sales people. First, I find people from my industry. Then, this is how I quickly filter them: what was your quota, did you meet them? I let the numbers talk. I have no idea how this will work. We'll know more over next few months. My cofounder-on-trial comes from a sales background where he did 60K in sales over a year as an intern.
One major suggestion I would give you is to take a sales class at the best uni around you. I took it around the time I was negotiating my first reseller contract. My professor really helped me in negotiating the deal all the way to close. But most importantly, I learned really different ways sales can be structured that we tech folks would never imagine.
Good luck!
