Many of us clip our dogs nails. If you are getting any bleeding you have cut into the quick, and most dogs will make you well aware of it, because it hurts.
In a year and a half I have only ever nicked the quick once, and she was squiming, so what I lined up in the nail cutter wasn't what I ended up cutting.
With black nails it's harder to see where you should be cutting and takes more care and practice, but white nails the quick is fairly easy to see.
They sell stop bleed in most pet stores in the aisle with brushes and clippers in case you do have an accident to immediately stop the bleeding. Corn startch works in a pinch though.