A lot of the details depend on what level person you want to bring in. My 2 cents, having done this bootstrapped more then once before, is to hire in good mid level sales people who have networks in the space you are in. Do not hire a VP of Sales or similar type role, hire in a few sales people and dice up the pie and let them compete, the one who does the best, find more like him/her and help the others learn or cut them if they can't make it to the same level. Once you have a small team that is selling and has made some progress then you can start looking into hiring a sales manager/VP of sales etc.
One (of many) mistakes I see too many startups make is hire some high end VP of Sales because the founders lack sales experience and think you need that person to lay out a plan for the young company. Yes, a good VP of sales can lay out a plan, but there is a massive difference between someone like that and a person who just pounds the phones, emails etc to get sales moving. Get people to get sales moving, to learn what works/doesn't work and measure how and what they are doing so that you can refine a system and train new people. Then when you bring in a more experienced VP they can take that basic system and scale it and tweak it in ways you don't understand (yet) and things will grow.
I like to iterate on sales like you would engineering, most good sales people I know do that naturally too. So don't be shocked if you go through quite a few sales people till you find a fit for your team and market. That is fairly normal in my experience if you are moving fast. If you are moving slower and can take more time then you might go through fewer but your lead time to hire will be much longer. Just tradeoffs.
As for finding them, look to competitors in the same market space and hire away their mid level people, or find people that have sold in a sister market. Targeting people is usually a good way, over placing ads and most recruiters can help you with this if you don't know how.
Interview sales people with normal questions and by introducing them to your product and then have them sell you on it after a 10-15 minute intro & question session (pay attention to the questions good mid level sales people ask lots of detailed questions typically). They'll screw things up in that presentation, see who can dance on their feet and not lie, embellish or back themselves into a corner. Pay attention to how they handle being in that position cause it will happen for real in 6-8 months on the job too.
Compensation can be hard to figure out at first so it will take some time, work with them to find a balance between what motivates them but doesn't break you or upset your balance. I always avoid equity on sales positions and they generally want cash anyway.