There are a few simple terms you need to learn before getting into DSLR photography...I don't have a lot of time so I'll make this quick.
Aperture: Look for the marking on the knob that says "A" or "Av". This stands for aperture priority mode. The smaller the f-number is on the screen, the larger the aperture (or opening of the blades in the lens) is. This allows your camera to increase the shutter speed automatically to the maximum possible speed to reduce blur in your photos.
Shutter speed: the time interval in which the photo is taken. Usually looks like a fraction (1/250, etc). The faster this speed is, the less blur in your photos. Manually set the speed to 30 seconds and set the camera on a tripod to capture long lines from lights in heavy traffic!
Viewfinder: USE THIS. Stop using the screen. Look through the lens of the camera and you're bound to get better at 'seeing' the potential photos around you!