We highlight a number of free online courses in our Lifehacker U series, and MIT has a one on documentary photography and photojournalism that is worth checking out. It's open to the public, and it will teach you new photography skills and help you improve on old ones.
Make no mistake, there will be readings, assignments and exercises to complete. However, the class is presented online in its entirety, and it's not instructor-led, so you can do it at your own pace and on your own time. The class is presented the way it was taught in 2009, so it's not necessarily new, but the lessons you'll learn are timeless. Hit the link below to check it out and get started.
Documentary Photography and Photojournalism: Still Images of a World in Motion [MIT Open Courseware via Gizmodo]