HyperHistory is a wonderful site on World History, including maps and timelines running from early civilizations to the present.
Fantastically done, although we definitely find the map of early civilizations to be outdated. It completely ignores megalithic civilization and the consequences for historical analysis brought by what Colin Renfrew labelled the radiocarbon revolution. Just change the date of Indo-European migrations to ca. 5500 BC (as per Gimbutas) and you will have a more accurate picture of what actually happened.
Still, this is a nice place to pick up a good general overview. What are especially good are the timelines, e.g. of famous people of history.