Automator should be able to help you out. You'll probably want to use a mix of the "Watch me do" feature along with some of the prebuilt actions.
It can certainly be confusing but here is the basic idea: On the right side of the Automator is your workflow area. All of the lists of prebuilt actions or modules on the left side can be dragged across into your workflow. You drag a series of these modules/actions together to accomplish what you want. Each action or module has input and output. Files are passed into that action, it does something with them, and it hands them on to the next action. With the watch me do feature, it will build custom actions based on whatever you "record" into Automator.
Hope that helps out a little.