10 Terrifyingly Huge Rodents - look at #4 (Josephoartigasia) and #6 (the modern capybara)
Capybara: Biology, use and conservation of an exceptional neotropical species - this is a PDF of an entire book. Isolated chapters will be of use, particularly #1, #2. Enjoy any you find interesting
Giant fossil rodent had an awesome bite - from National Geographic. Specimen of Josephoartigasia from Uruguay.
Hydrochoerus hydrochaeris from Pleistocene of Brazil
Capybara fact sheet - modern capybara information; also see chapters in Capybara: Biology, use and conservation...
