I have become almost reliant on a great FREE mind mapping application, Free Mind
It allows you to hyperlink to other nodes, to other pages, to external files and sites. I found it extremely useful when I studied for the GARP FRM exam. For exams, you can create an overview node with the main topics of the curriculum and then break out in detail a new page per subject. Related topics can hyperlink between each other, then you add links to youtube or PDFs. It really helped me.