Darwin Day is "a global celebration of science and reason" held yearly around Charles Darwin's birthday, February 12th. Their website provides a listing of events related to the celebration, and their locations.
This creator of this site does a wonderful job of providing step-by-step maps of Darwin's voyage on the H.M.S. Beagle and a historical context for the time. Also, check out the comprehensive set of links grouped by topic.
Cambridge University Library provides a searchable database of the synopses of Darwin's letters. A prolific epistolarian due to his ongoing poor health, here you can get a flavor for what Darwin was thinking and a sense of the Victorian times he operated in.
A wonderfully comprehensive online version of the popular traveling exhibit. It traces his life and provides audio and video of experts, images of his corrspondence and collections from the Beagle, and even a tortoise cam.