HTML Goodies is a site dedicated to offering help with any topic area that goes to building a Web site. To that end, there are tutorials covering everything from basic HTML all the way up to fully-functioning PERL CGI scripts. That's my navigation bar. It's on every page. Goodies runs a hierarchical navigation format.
Big topics lead to tutorials under that topic.
The navigation bar is set up so that the easiest stuff, the primers, are up top. The hardest stuff is towards the bottom. The Master List page is my favorite method of finding what I want. It's a very long page with a link to every primer, tutorial, script tip, chart, and reference piece on the site. I personally use that page the most.