Your business values are the underlying core principles that the business will operate under. These are the non-negotiables, beyond policy, that define the business behavior. There are various support tools for helping you define these, but my recommendation is to choose between three and five. More than that and no one will be able to remember them all and that is what you want. You want all your key stakeholders to be able to reel them off without hesitation. After all, these are the non-negotiables. You don’t want your people to have to look them up every time they refer to them.
Your mission is where the owners want the business to go. It should be a relatively simple statement of where the business should be headed and over what time period. There are various schools of thought, but I’d suggest around ten years. Its long enough to allow changes in strategy to get there but within a timeline that people can conceive. I like ten years because you can divide the period up into some strategic phases or horizons. For instance, you could break ten years in to two phases of three years and one of four years. This isn’t “hard and fast” but just an indicative guideline.