Here are a few images of a centipede bite:
As you can see the bites vary in severity depending on where it is on the body, how bad the bite was and what kind of centipede did the biting.
When a centipede bites it is not actually its teeth that do the biting, it is the pincers that are on the front of the body that pierce the victims skin and injects poison into it.
The red around the bites on the pictures is the venom from the bite spreading under the skin.
As you can also see from the pictures, each 'bite' is made up of two wounds, these are from the two forcipules. It is hard to make out from the pictures but each wound is chevron in shape, as this is the characteristic shape of the forcipules.
A centipede bite can be quite painful, and this is largely due to the venom. Usually they are not life threatening and there are treatments available to ease the pain and the swelling. However there can be some complications if someone is allergic to the bite.