The problem is that if you create your doc via Google docs and print or save it as a pdf - Sometimes the hyperlinks are lost in the final pdf file..... (This especially applies to your clickable table of contents).
So what can you do to retain any lost hyperlinks and your clickable table of contents?
It does take a few more steps but is very simple to do:
1. Create your Google doc and add your hyperlinks and clickable table of contents
2. Download the doc as a .odt document
3. Upload your doc to http://www.freepdfconvert.com/ (there is a free and a paid for option)
4. Download the newly created (for free) pdf doc to your computer
5. Share the pdf with everyone (or upload the pdf to Google drive and share the links direct)
It does take a few extra steps but is very fast and simple and solves the problem of Google docs not retaining their hyperlinks when saved as a pdf direct from Drive.