Building a supply of breast milk

Hello ladies, I am a FTM, I intend to breastfeed when I give birth, however I don't know how long I will be able to physically do it myself for. I would like to stock pile & freeze the milk so others can feed him & he will still have the benefits of my milk. Can anyone give me advice about how often I will need to pump/ how many times a day, how long will a pumping session last once I get a good rhythm, should I only pump around feeding times or should I do it inbetween feeds? Any help on the matter will be appreciated xx