shared calendars

My wife and I use shared calendars across our multiple Mac devices. However, we are going nuts - because all we ever wanted to do was enable the other person to view our calendar as and when they need / want to.

What we actually get - is notifications continuously coming up on each and every device for the other persons events. Most of which are totally irrelevant and not wanted. It's made worse, because I have to click 'ok' on two Macs, an iPad and an iPhone - for each thing.

I've previously tried this at the Genius Bar - but their expertise was sadly lacking in this respect.

Any ideas?