Think of free will as the 50-50 elements within a system of permutation. No matter how complex the permutation grows, it always has two elements that are both equally 50% positive and 50% negative. When human beings encounter these 50-50 elements in every day reality, they are left to choose between a statistical positive and negative. There is no way to decide, without external influences, which choice to make. The brain comes up with a solution that is based on experience, affinity, and random information. What we call free will.
People do everything for a reason. If a reason is a cause, then people do not have free will. That's all there really is to it. How much free will actually affects your day to day life depends on how important your decision is. According to most religious, free will is not really free. If God "allows" you to have it, that's not free, it's borrowed. But you should stay away from absolute statements like "There is no free will." Stuff like that can bite you in the ass later, logically speaking. I prefer stand on a term known as "compatibilism," it is makes more sense to me.