The answer is simple. Establishing a value for the assets you have available to sell is the single struggle of someone selling their business. What you think something is worth doesn't mean anything if someone else isn't willing to pay it. Reaching the middle where you both think the exchange is fair is the only struggle.
Sure there are elements that contribute to that you might call struggles, such as explaining your business, transitioning control to a new owner, preserving good will of customers during the transition, proving revenue, etc. But they all roll-up to establishing the value.
This is too vague to answer. Do you have a business you are trying to sell (see Paul's comments) or are you trying to "sell" others on why your business ("huge dream and an idea") should be valuable to them, and ultimately to you?