good, desire, choices?

Through out Book I Aristotle tries to define the term of Good and how we apply it to life (as ordinary people and philosophical people) and the more in depth he goes with is explanation, the more his definition seems to be blurring. I gathered that Good is a human trait, one that we tend to confuse with materialistic need. Aristotle in a way is saying we should enjoy things for more than just face value.But how do yo identify the good? Is the good there because we were raised to think one way about it or because we came up with that conclusion ourselves?

But in book III he talks about desire and choice and how they do not go hand in hand. I don't understand how you can't desire desire and that no choices have an emotion attached to them. What is the definition of a choice, how can it not be attached to an object or a specific thought that can be good or bad? Could desire and choices be another form of the Good, but a version that has been muffled? Maybe a version that has been down graded or even upgraded, depending on how you look at it?