Discounts to a product category

[Trasgu]

If I apply a discount to a product category should be able to see the real price and the discounted price on the list of items in the store.

I want the customer to know that those items in that category are a X% discount.

What I have to change to see the real price crossed out and no discount?

Thanks.

[ChrisLNZ]

go to product and edit
Midway down is a section for pricing - gives option for discount and also if you wish displaying "sale: sign

[Trasgu]

Thanks ChrisLNZ. The problem .. I have 5000 products.
From the menu of customers - groups, you can define a percentage off for your products by categories. The problem is that the front-end is not the original price of the item (or that is lowered). That's the problem.
Modifying the template, it would be easier, but not how. Please HELP. Thanks in advance