There are also coaches who can help people be more effective because they are trained in improving the soft side of an individual's approach to leadership. These people typically are educated in management development and typically come from the HR side of the house. The ability to ask hard questions is a necessary skill of any good coach. The goal of coaching is to motivate behavioral change. This requires the establishment of a strong relationship between the parties.
Good coaches are usually good bosses.
Look for leaders who have no problem recruiting or retaining talent. Also look for managers who develop relationships and mentor people over the long term and the ones that others seek out for advice. Specifically, in terms of skills, good coaches have great listening skills. Other good coaching skills include the ability to read organization politics and climate, infectious optimism, and a heavy dose of pragmatism as the coach helps define an approach that will build on small wins. I'm not sure if this question is from the point of view of the IT worker who coaches others or received coaching.