The Natural History Museum website has a lovely, interactive account of the Voyage of the Beagle. Seeing it plotted on a world map helped me to appreciate its significance a little more.
I was alerted to it by a history course I am taking at Coursera, which makes available university courses, mostly from North America but also from other countries.
Courses of various durations covering a wide variety of topics are available, free of charge. Good quality material and presentation. Well worth a look if you don't know it already.