Pro Tips

Shutter speed controls ambient light. Aperture controls flash exposure.
Manual shooting requires your consideration of three variables; Aperture, Shutter Speed, + ISO.
Telephoto lenses can compress a background, making it appear as though it's closer than to your subject than it really is.
The blurring effect of a background is called "bokeh".
The higher the ISO number, the more the quality of the image suffers. Unless your being artistic, always shoot at the lowest ISO possible.
The amount of light falling on a subject decreases by 75% every time the distance between the subject and the light source doubles. It's called The Inverse Square Law, and there's no cheating it.