I took an introductory Philosophy class last semester and had to write a short paper on this topic (but of course my knowledge is not extensive by any means). We read pieces by Hume, van Inwagen, Chisholm, Susan Wolf (who, out of all these philosophers, has the most interesting ideas in my opinion), and Galen Strawson. If you're interested I can get you the titles.

Anyway, the short of it is that I "believe" both free will and determinism exist, and they work together. I go by Hume's definitions of free will (doing what you want) and determinism ("the constant conjunction of similar objects and the consequent inference from one to the other"). If determinism is what allows us to reasonably gauge the possible consequences of our actions, then we need it in order to have free will (how can we know if we really want to do something if we aren't sure of the consequences?)

Honestly I haven't thought about the concept of free will at all since writing the paper. It is an interesting topic, but the more I think about it the less I can really settle on one "side" of the argument.