I think it is your preference. Keep in mind what you will be using it for. None that are specific to coaching. I would recommend a good word processing program, a good accounting program and a good data base management program. Currently, I'm investigating working with Delta Road - I think it's a good start.
Marketing is the most difficult part about coaching, or running any small business.
To market to corporations you will want to think about doing cold calling, sending out marketing materials and networking where the people in the industries you want to work with hang out. A good place for that is at conventions, conferences, chamber meetings, places like that. An hour seems somewhat long. Typically a coaching session lasts between 30 and 45 minutes. Sometimes as long as an hour depending what is being worked on.