The Great Lakes of North America:

Great Lakes Atlas by USEPA-Environment Canada
The Great Lakes: Superior, Michigan, Huron, Erie, Ontario, USEPA
The EPA-GLNPOVisualizing the Great Lakes site
Glossary of the Great Lakes
GLIN- the Great Lakes Information Network
The Great Lakes overview, from GLIN
The Great Lakes Ecosystem, GLIN
Lakes of the world, ILEC
Large Lakes of the World - table, containing some of the common errors, but useful in general...
 

Other important large lakes of the world:

Lake Naroch (Belarus) Description and overview from ILEC
Lake Nipigon (Canada) Description and overview from ILEC
Lake Hovsogol (Mongolia) Description and overview from ILEC