Make a +5 magic at the New Londo Ruins blacksmith, then you can enchant from there. You'll need the ember from the treasure in darkroot (it's a chest in the water with the 2 large mushrooms.)
edit: I think you mean enhance not enchant. --- LOL@console fanboys. Just because it's the only console YOU own doesn't mean the others suck. Great games on all systems. Get over yourself, shut up and play.