I have a very complicated pdf with many links. I need to link individual words to files that are in a series of folders. How can I link to a folder instead of just a file?

If you're linking to PDF files then use the "Go to a page view" command and then link to the specific location in the file that you want to launch when the link is clicked. If you're linking to other file formats then use the "Open a file" command. Just remember that these links are relative (if the other file is on the same drive as the source file), so if you move the PDF you have to move those files and folders with it, or the links will be broken.