Well, it's pretty simple. You just click where you see "-on", over in the menu, next to the "Help" option. That will turn on a bunch of little help icons all over the site, each of which links to some information related to the page context where the icon appears.

The help icons can also be accessed via the preferences page. To learn more about the preferences page, click on "-on" in the menu, as described above, to activate a help icon to the left of this paragraph.