To link one word or a paragraph to another (e.g. in a table of content) highlight the part of the text that you wat to turn into a link. Then click on Insert -> Hyperlink.
A window will open (see Attachment) in which you are able to define a website, an anchor within your document or an email address as the destination of your link.
Click "Ok" and the link is generated.
To delete a link place the cursor right at the end of the linked text and click the del button.