Dennett, Pinker, and Sam Harris have short talks on free will.
Dennett and Pinker have some insightful clarifications of the issue. Harris is probably influenced here by Buddhist ideas about the skandhas but his ideas are hopelessly muddled as he adopts the dualism that he rails against. (You get the feeling of physical causes of mental states--a very naive view of science: psychological processes are simply an explanation of the same processes which can also be explained in terms of physical processes.) Pinker even falls into this briefly if we consider his language (his wording that psychological processes are "the product" of physical processes.)
I think a good place to begin with this question would be to start with a phenomenology of free choice. If we do that as the first step of a scientific investigation and then go on to investigate these processes with all the methodological tools are our disposal, we'd find that it makes perfectly good sense to talk about human choice, that there are physical correlates to psychological processes involving choice, that these correlates (along with the psychological processes) are bound up in cause and effect, and yet, from a phenomenological perspective, these processes are exactly what are involved when we experience choice and freedom.