Delegating is easy. The hard part is mentally releasing from the delegated responsibilities. The ability to mentally release is directly correlated to the level of trust in the person responsible, as well the magnitude of the task. While neither of these should be taken lightly, we must allow people the chance to prove themselves with increasing responsibilities.
Not only does it help them grow, it helps you become more productive and a better leader. Your team mates want to help, but they need you to let go of tasks and decisions they are capable of making on their own.