I just got the html5 & css3 book and was really excited to dig in. I'm not entirely new to html or css but with this book I'm lost. I don't understand what is a h5o link is or where to find it to display a document outline. And I'll save my exasperation with the forms chapter for another thread. Please help.
h5o - HTML5 outliner (bookmarklet, Chrome extension) - Google Project Hosting
That is the link for the HTML5 Outliner. You can install the chrome extension or use the html link to create a bookmarklet in IE or Firefox. Keep in mind that the chrome extension will not give outlines of any local documents rendered in that browser. I like the h5o more than gsnedders which is another popular one.