I'm a single man non-technical founder. Its a lean startup, and we're doing some killer customer development.
First, congratulations on giving this important topic some consideration before you find out that your team of 20 don't get along or work productively together!
Building a strong team and determining your talent requirements share one thing in common: clear objectives.
Before you post your first job ad or interview your first candidate, it's imperative to be clear on your company's vision and values. This is as critical a metric for team building as determining what skills you need. You may be successful in hiring skilled and experienced people, but if they don't work well as a team, if they don't respect one another, if they don't challenge each other to grow and get better or support each other when times get tough, then the business doesn't move forward (or worse). Be clear about what you see the company becoming, what core values & guiding principles you expect from yourself and your team, and hire those who demonstrate the greatest passion and humility. This will create a solid environment for amazing teamwork to thrive.
To determine what kind of talent you need, start from the 'top down', not 'bottom up'. Focus on your business goals and objectives first. Creating an org chart and cobbling together individual job descriptions based on your current needs may meet your immediate requirements to get work done, but it may not be scalable, or your resources may not be properly allocated. Think ahead as best you can to ensure that everything that everyone does is working toward achieving your goals and objectives.
I would welcome a call if you would like to talk further, but in the meantime here's a link to a recent eBook I wrote on team building. I hope all of this has been of some help!