Below is a list of helpful links:

• Will guide you to almost any business mailing question you might have.
  • http://pe.usps.gov/
  • http://www.usps.com/
• All things relative to postal pricing
  • http://pe.usps.com/cpim/ftp/manuals/dmm300/Notice123.pdf
• Postage Price Calculator
  • https://postcalc.usps.com/?_ga=1.168237025.1950610653.1485290966
• Primary source for USPS mailing information
  • https://postalpro.usps.com/