MyThoughts for Mac makes it easy to add Links to Files, and Pages on the Web, it's just a matter of drag and drop. This is a great feature when your Mind Map is an overview of a much more complex subject that has supporting documents and data. Or maybe you want to link to a Quicktime video that relates to your Thought.
Add Notes to your Mind Map Branches using the Notes Editor, format them to suit your needs, the options are plentiful. And, when you wish to add a cross reference, one click on a check box and Outline Numbering is applied. Many more features.