When in Varadero, you'll want to spend a day (or at least a half day) in town. I like to take the double-decker bus and get on-and-off as you like.
There are plenty of places to shop and sights to see. Here are a few pics of places to shop.
A lot of the same souvenirs can be found at various stores, but many of the items are made right on site by the people there.
Here is a mall: Centro Comercial Hicacos. It's quite different than the various street markets with groceries and small boutique stores. It's a great place to get coffee beans, rum, or cigars to take home with you.