Problem specification - Adding a Table of Contents.

The aim is to be able to show a complete novice to HTML, how to add a Table of Contents (TOC) to a page inside a pair of div tag (with id="toc") provided for this purpose. Initially the TOC should list all H3 headers. and each item in the TOC must include a hypertext link to the relevant (h3) paragraph. Then having established a procedure, to use javascript to achieve the same result automatically.