If you write longer blog posts and want to give your readers a structured way to navigate your pages and posts, the free Table of Contents Plus plugin is an elegant solution.
It automatically generates a Table of Contents on your page from section headings, resembling very much the great collapsible Wikipedia style contents boxes shown to the right.
Adding a table of contents to your WordPress posts not only helps the reader see and navigate what’s on your page, but it also helps Google generate structured links in search results.
ToC+ can also auto-generate visual sitemaps and indexes of your content.
I’ve written a full tutorial for using the Table of Contents Plus plugin at Tuts+:
Add a Beautiful Table of Contents to Your WordPress Posts
You can also see it live on this site here:
Installing WordPress at Digital Ocean