How to watch
Head over the the offical 24hseries.com website, they have a stream linked for the race and some earlier sessions.
About
Started in 2006. As the organizers stated back then, "... the series aims to create endurances races where (semi) professional drivers as well as amateur and gentleman drivers can participate". Longer formats preferred, so you're most likely to see races between 12 and 24 hours. With the odd 6h sprinkled in.
Official Website