TOC - Building a Front Page - Help Authoring Site
The Word TOC cannot be used because it is automatically generally by Word and therefore any links will disappear when Word update the TOC.
Most people handcraft a TOC for Web and Help because they generally look better when done in this way. The front page may well have icons etc.
However try using the 'AutoTopic' feature on the 'Extras' Toolbar ... this will build a basic TOC for you, from all the jump Topics in your document.
There is a new feature called EasyContents that will build a list of links from any topics of any style and at any point in the document.