Best way to implement discounts
I was wondering if anyone can offer some suggestions on how I can implement a discounts feature to my site.
My client wants to give a % discount when the number of items exceeds x value (i.e. 500) but they want to manage the % themselves through the backend pages I am building for them. They also want the ability to offer free delivery (shipping) if the order value exceeds x amount.
Ok so how do I go about this? By the way this is the first time I am trying discounts. I assume I pass the % in a session variable but I'm not entirely sure how to pass the variable into the calculation. I have read through forums and the help documents but I've not really been able to grasp the best way to implement this.