Non-lethal attacks are half damage. Once you bring a foe to 0 hits that way they are subdued.
Some attacks (one example lightning) cannot be made non-lethal. For your attacks check with the GM. Only blunt weapon sneak attacks can be made non-lethal.
The condition for being bloodied with non-lethal damage is different. It is referred to as 'roughed-up'. When you are roughed up you are -2 on to hit, damage, and saves. You are -2 on any roll vs intimidate or will.