Buyers are looking for businesses that are ready to go. An ideal purchase for a business owner would be a business where the operating manual was so good that someone with a minimum amount of intelligence and experience would be able to buy the business and run it. Not much training — just read it and go.
Few businesses are this simple but I would suggest that you can add to the value of your business if you have really good documentation around your business processes.
We would even consider this to be intellectual property.