A question I get at times is "why don't my items show up?"
If your store is open, you need to mark each item as being "on sale". That doesn't mean your item will end up in some drastic price reduction, it just means your items will be listed when customers browse the mall.
If you are logged in to the mall, previewing your store will show you all of your items, even the ones not on sale yet. A good tip to check that everything is showing up ok, is to log out of the mall and view your store as a customer. If you can't see your items, neither can they.