Contrast enhancement is "dynamic contrast".
The aspect ratio matter if you watch different tv channels or the tv get different input from different sources. Some tv shows use 4:3 and some 16:9. On a widescreen you get a "pillarbox" when displaying 4:3 correctly. Its a black line on each side of the picture.
With a pc youre software should take care of the aspect for you. If you set a resolution that the tv dont support, youll get no picture..
"Auto Motion Plus" is what youre samsungs "image smoothing" feature is called.
For the most accruate gaming picture its prolly best to turn off.
For tv shows and sports its prolly gives a less choppy picture. Good movies and series are allready smoothed and tampered with, so it prolly dont matter.
Samsung seem to have something called "Edge Enhancement". Try turning it off.
Sharpness enhances the edges of a picture. Less sharpness means "smoother" picture. High sharpness means sharp edges and "grainy" picture.
Backlight is like having a lightbulb where the dimmer is the backlight. Every screen have different amount of actual light it emits.
This tread actualy got me to start tampering with the contrast and brightness again. Less brightness actualy gives a better picture i think.. With C:75 B:62 i seem to get more colors..
I feel slightly obsessive 
By the way, the calibration dvd..dont you need a calibration tool for that?
Edit: Misleading typo.
Then my aspect ratio is 16:9
So the less sharpness the better for the game? I think the sharpness sucks when it comes to the edges of each picture, but does it have any other uses?
I have no experience of knowledge on calibrating tools or software.
But like the other guy mentioned I'll prolly just get the DVD when I get time.