Charles,
I, too, used to struggle with delegation because I felt the responsibility for the task. It was important that I change my perspective and look at what the employee might gain as a result of completing that task. By not delegating, the employee is deprived of the opportunity to learn new skills and to gain a higher level of visibility. It means, too, that the supervisor has to be selective in determining which tasks to delegate to which employee so that the employee does indeed benefit. The supervisor stills retains ultimate responsibility for the successful completion of the task and guides the employee when/if needed to assure that success.
Pat