Hello Ralphliu, sorry for using english. I am at work and have at the moment no chinese input system. If you like, I can also write in German. To your questions:
1) I personally would prefer to write in sections (like in English)
2) I would propose the following sections: prehistory (Vorgeschichte - ca. 50 BC), roman time (Römische Zeit ca 50 BC - 400), early middleage (Frühmittelalter 400 - 900), middle middleage (Hochmittelalter 900 - 1400), late middleage (Spätmittelalter 1400 - 1600), Renaisance/enlightment/absolutism (Aufklärung und Absolutismus 1600 - 1790), Vormärz (don't know the english word, 1790 - 1842), empire time (Kaiserreich, 1842 - 1919, include I WW, 1842 - 1866 is not yet empire, but it should be handled together), Weimer republic (Weimarer Republik 1919 - 1933), Third Reich (Drittes Reich, 1933 - 1945), After war (Nachkriegszeit, 1945 - 1990), Reunion (Wiedervereinigung, 1990 - )
3) As you would like and your time allow ;-)
4) Be careful, all books have copyright, almost all websites also have copyright.