Calendars on two computers & phones

Hi all

I am still unclear as to how I can have seperate Calendars for my wife &
myself with the ability to be able to Look at and edit each others
information from our home computer or our laptop or our moblie phones and
still keep everything in sync.

Can the above all be done?
If so what software/programs do I need?

Anyone already doing the above, I would love your input.

many thanks
Andy