During the first few weeks a baby's nails are still very soft and should not be cut yet. The nails may be rubbed with oil so that the baby does not injure himself. This makes the nails softer and less dangerous.
As soon as the nails begin to harden (ca. 6 weeks), it is important to cut them regularly. It is best to do this while the baby is sleeping or while it is being cleverly diverted. It is important to cut the nails as short as possible and to round off the ends. Then no "sharp ends" will remain that might be a possible source of injury.