A band-aid should stay applied for 1 day (until next morning). Try not to get this area wet. The next day, the area should be gently washed with soap and water and covered with antibiotic ointment and a band-aid twice daily. Also, if possible, rotate the position of the band-aid after each cleansing.
After two or three days, you may not need to cover the wound with a band-aid, but continue to clean twice daily and apply antibiotic ointment.
To avoid getting a scar you may want to continue using a band-aid to cover the area for at least 2-4 weeks. However, to have the best results preventing scars, you should use Silicone Sheeting like ScarAway (which has been proven to prevent scars and eliminate existing scars).