if you look at gregs 9 ball rle you might understand better. the path you swing your club is the ballistacal flight your ball will take, if your ball goes strait at first then that is good, that means you have an in to in swing. the reason it curves left or riht later on in flight is becuase the club face wasn't square at impact. it puts side spin on the ball. after a certain amount of speed is lost then the aerodynamics of the ball kick in and it responds accordingly. if you watch a pro or someon with high ball speed hit, if they slice, it will usually not start curving untill about 50-80 yds of ball flight. aerodynamics is also what causes the ball to rise in flight after hitting it as most pros do with enough backspin, but too much backspin can be bad and as it causes the ball to rise too much and then it falls short.

to draw the ball you want a in to out path and a closed face what you are really doing is hitting a weak push hook. but they are aligned right of the target so itdraws back.
to fade it you want a out to in swing with an open face then you are really hitting a weak pull slice. but they are aligned left of the target so it fades back. and to hit it strait you want a swing path that goes in then square and back to in with a square face at impact.

as far as how far to stand, it depends on how flat or steep your swing is and if you are a one or two plane swinger. if the loft on your club is standard then you determin how far to stand based on just letting your arms hang naturally...... usaully an iron has steeper aproach and your hands are about a fist away from your body and a driver you want to be flatter and so you have aobut 2 fist difference.

sounds to me like you have a strait slice, try to get a stronger grip, or maybe you are fanning the club open on your backswing making it hard to return it back to square at impact.