To navigate from the main menu, click on one of the icons corresponding to a section. Or click on "site map" at the bottom of the page. To navigate the secondary pages, choose one of the icons on the toolbar. If you hold the cursor over one of the icons, text describing section the icon corresponds to will appear. Or, you may scroll down to the bottom of your page and click on the link to the next section.
To help the reader understand, a reference toolbar is available at the top of the screen.
For trouble in understanding chronology, the clock icon goes to a timeline.
For trouble in understanding geography, the map button goes to a 3D map.
For trouble in understanding vocabulary, the book icon goes to a glossary.