DIN is a sans-serif font. It goes well with Open Sans, Lucida Grande, Helvetica Neue, Ko, Merriweather, Apercu Mono, Pr, signpainter, Edmond Sans and Dyna. If you're thinking about using DIN then try 30px for headers. Give 16px a shot for content.
People commonly tag it as din, design, sans serif, ecommerce, magazine, retro, classic, poster, modern and app. You can get it from Fontdeck, Fonts.com, Fontshop, Fontspring, MyFonts, Typekit and YouWorkForThem.