Marc Levoy, a principal engineer at Google and a former professor of stanford has offered free lectures on Digital Photography. You need not have any prior Knowledge on photography to go through this course. This course is based on CS 178(Digital Photography), which Levoy taught at stanforn from 2009 to 2014. It gives an introduction to the scientific,artistic, and computing aspects of digital photography. The course consists of 18 lectures. To improve your picture taking skills and develop good photographs are pretty good reasons to take up this course.
Topics include lenses and optics, light and sensors, optical effects in nature, perspective and depth of field, sampling and noise, the camera as a computing platform, image processing and editing, and computational photography. This will also include survey of the history of photography, look at the work of famous photographers, and talk about composing strong photographs.
The videos linked on the web pages are from the google lectures which are edited later to remove discussion of the google internal projects. Except for few photographs which are copyrighted other are freely available for everyone.
As it is a digital photography course you may need a digital camera, particularly one with manual control over shutter speed, aperture, and ISO. It's also helpful if your camera has a variable zoom lens, but surprisingly, manual control over focus isn't as critical, since you can easily "fool" your camera into focusing at whatever distance you want. Your camera should also have a flash, as most do. You don't, however, need an SLR (single lens reflex camera). Many DSCs (digital still cameras, also known as point-and-shoots) offer enough flexibility. So do Mirrorless Interchangeable Lens (MIL) cameras. A cell phone won't suffice, though, because it doesn't have a controllable aperture.
Free Course Video
50 Different Types of Photography Styles with examples for your inspiration