History Channel - http://www.historychannel.com/
On the left side of the screen, click on the decade you wish to explore under the heading "Select a Century".

HyperHistory ONLINE - http://www.hyperhistory.com/online_n2/History_n2/a.html
This resource has links to timelines on scientists, composers, famous women, artists, politicians, and more.

Timelines of History - http://www.islandnet.com/~kpolsson/timeline.htm
Nice links about technology.

Events in Science, Mathematics, and Technology - http://www.gsu.edu/other/timeline.html
This page provides a collection of timelines.

Who What When: Interactive Historical Timelines - http://www.sbrowning.com/whowhatwhen/index.php3
This is a database of people and events from 1000AD until now. Lists of explorers, musicians, mathematicians, scientists, authors, architects, artists, and more are available.