Do I need to sterilize my baby's bottles?

No. Nothing after birth is sterile, and it's not necessary to "sterilize" bottles or use boiled water. Use the dishwasher and tap water.
No. Though there's no harm in it, sterilizing babies bottles usually is just creating extra work for parents. In most cases, just cleaning the bottles with warm, soapy water should be sufficient. Some experts recommend sterilizing the bottles for the first month of life in households that use well water.