There are plenty of sources online that guides you to using your DSLR.
Here’s a list of the ones I’ve found useful.
In addition to reading stuff like this, I think that reading about photographic composition, learning about the crucial importance of lighting, taking art classes, looking at works of photographers you respect, developing your personal vision of photography and so on are critical if you have any interest at all in the artistic and creative aspect of photography.
But most importantly, go out there and shoot! The only way to improve your photography is to take more pictures. Shoot a lot, go over what you’ve done and decide what worked and what didn’t. No amount of reading can make up for practical experience.