Delegation is probably the single most essential skill you as a business owner need if you want to have a great exit from your business. We advise all business owners that if they want to sell their business, it can't be dependent on them. If you are essential to the business it is either unsellable, or the price will be a fraction of what you expected and/or you will be required to stay on for at least another 2 years to develop the leadership abilities of those staying before you are free of the business. It is a now or later situation, learn to delegate now so your leadership team (that is staying in the business) can prove they have the ability to grow the business regardless of your involvement or learn after you get a purchase offer that makes you choke. So if you want a great exit when the time is right, learn to be great at delegating.
This fast company article "How to Manage if you Suck at Delegating (and why it is an important skill to learn)", provides some good advice on what real delegation means and how it is the key to building the leaders around you. This article "12 Tips on How to Delegate", provides some good instructions on how to do it.