I'm looking to write a script that will move all file in the downloads folder (once fully downloaded) to different folders on the hard drive and external hard drive. Where can I learn more about how to do this?
You could use a folder action like this:
Or create rules like this in Hazel:
This is the Apple official documentation regarding Applescript.
Here are two other tutorials, all obtained through google when I was learning myself.
I found both the above very good.