This week I've chosen Light Stalking, which is a magazine-style website that showcases great photographs. There's always something new to read, the articles are well-written, the photos are amazing, and you get an introduction to the work of lots of top-notch photographers. The credit links alone can have you buzzing around the net for hours! Light Stalking also write tip-style articles, and occasionally review photography books and gear. They're very active on Twitter and Facebook, so you don't even have to visit their website to get your daily photo fix.
When you first visit the site there's an annoying pop-up inviting you to subscribe to their newsletter, but other than that, the site is fairly user-friendly. The advertising is pretty low-key, and it's all relevant to people interested in photography (no promises of weight loss miracles or making millions working from home!)