I can't beat Ornstein and Smough?

Try to keep them separated as much as you can. Usually taking out Ornstein first (the smaller guy) is easier, but you get the item drops of the one you kill last so keep that in mind.

Ornstein is weak to fire attacks, and Smough is weak to lightning in his first form and fire as well, so pyromancy is useful, or the lightning spear from Sen's Fortress if you plan on killing Smough first.

Worse comes to worst you can summon Solaire outside the boss arena to help you.

 I think whoever you kill last, is whose Demon soul drops. So .... I can take Smough out, but I need to get another weapon to handle super Ornstein. ..... I locked on the little guy and I kept strafing around him so that the fat guy is ... I am fast and have a ton of endurance with a 78 blocking shield, so I can ...