thanks, as far as contacts/calender go how do you decide which is the master copy or does it just collate the two (bb and mac)?

I have been using ical and mac address book longer than i have had a bb...so i have similar but different details on my mac and bb (bb contacts came from my last cell phone)....if i follow the procedure in the link will i end up with both sets in both places or will i have to pick one over the other.....does any of that make sense?