Opening shared exchange calendars

I'm trying to learn my way around this native exchange support in snow leopard. I'm stuck on trying to open other people's calendars. On a windows machine using Outlook there are many calendars I open on a daily basis. When I go into iCal and try to add those calendars through preferences > accounts > delegation those same calendars that I'm able to open in Outlook report that I have no access. What's going on or what am I doing wrong?

still looking for an answer...