Now I am a proud owner of Nikon D5300 DSLR equipped with an 18-55 kit lens. This is the first time I am dealing with DSLR. I don't want to use as a mere point-n-shoot camera, but want to use it to its fullest extent. I feel the need of taking a full-length, in-depth online free photography course which will take me to the DSLR world. Can anyone please suggest me any such course which explores the key areas in DSLR photography?
A good place to start is the Nikon Articles. It can be the next thing you look at after your camera's specific tutorial. Some topics include: Lenses: http://www.nikonusa.com/en/Learn-And-Explore/Query/h4lfxztn/nikkor-lenses.html ISO: http://www.nikonusa.com/en/Learn-And-Explore/Query/gyqh325g/iso.html Aperture: http://www.nikonusa.com/en/Learn-And-Explore/Query/h4l7gjbw/aperture.html Close-up: http://www.nikonusa.com/en/Learn-And-Explore/Query/h4l7gjcj/close-up.html there are many more with well-explained general information.
Another site you might wish to look at is Digital Photography School, especially this tutorial: http://digital-photography-school.com/megapost-learning-how-to-use-your-first-dslr/
The Adorama Learning Center has solid info on the use of DSLR's organized into a variety of topics. Lots of video to make it easy. http://www.adorama.com/alc/0014511/article/nikon-d5300-dx-format-dslr-product-overview
These should give you a starting place. There are many more great sites, although you sometimes have to sort through a bit of clutter to find the best ones. Good luck and enjoy your new equipment!
My answer would be the way I learnt (we are all "STILL LEARNING , BY THE WAY ") AND I COULD'NT RECOMEND IT MORE. U-TUBE, .....GO ON TO U TUBE AND TYPE IN ANYTHING YOU WISH TO KNOW, you'll be amazed at what you can learn.. heres a link to just one of many... good luck https://www.youtube.com/watch?v=mkhQK_8pu9U