"HDV" stands for high-def videos. The "black on white" is pretty self-explanatory. Put them together and you got yourself HD videos featuring interracial black on white content on Black On White HDV. This is a small part of a large HD video network, Premium HD Videos covering multiple genres, so that's really the site you're joining.
When you sign into PremiumHDVideos, they are nice enough to take you right to the BlackOnWhiteHDV channel and right there at the top of the page is a huge image representing the most recent video (which in my case is a pretty auburn-haired chick getting pounded doggy style by a light-skinned ebony stud). The material is network-exclusive, but you are likely to see it in a couple of the "channels."
At this point there are 106 nonexclusive episodes and each one comes with a set of high-res photos and a video that you can stream on an embedded Flash player or download in MP4 format. The movies are available in HD and there is a mobile option as well, so you don't have to choose between sitting at home and watching porn and sitting on the subway watching porn (the latter I don't really recommend).
The name of the site doesn't specify whether it is the chick or the dude who is black or white and that is because it isn't always the same for every scene. Sure, the majority of the flicks give you white babes and black guys, but there are a few white guy/black girl scenes and even a couple of mixed lesbian scenes.
The good news is that the site is updating. It seems that you can feast your eyes on a new interracial encounter about four times a month. That might be because they are updating the entire network almost daily, so individual niches don't get consistent attention. But at least you get access to the entire network of HD content – there are almost 900 more scenes covering categories from big tits to Asians and fetish and anal to ebony and group sex. Check out MILFs HDV and Lesbo HDV.
As it stands, you really should have an interest in the entire Premium HD Videos niches in order to get the most out of it, but Black On White HDV does have enough porn to be worth the asking price if that's all you're interested in seeing.