I found an old (January 2006), yet very nice article on the Web site A.M. Costa Rica, a Costa Rican daily news source, about how to prepare empanadas.
It goes into great detail about what empanadas are, their tradition, and how to cook them. It even has nice pictures that show you several of the steps you have to follow in order to prepare the empanadas.
Even though A.M Costa Rica has always had articles about Costa Rican food and restaurants, they recently created a food section, which I find very useful for those interested in knowing about Tico food, the culinary traditions, and where to eat in this country.
Accesing this site requires no registration, so I think it's a good idea to add it to your bookmarks if you are really into Tico food.
Here's an excerpt of the empanadas article:
"The empanada, the Costa Rican version of a sandwich, is easy to make. That's why they are available all over town.
But to make them you need a little time and patience.
Here the empanada is a breakfast treat but also eaten during afternoon coffee. And you will find it at the oh-so-upscale embassy cocktail party.
The technique is simple, and the types of fillings are as wide as the imagination. Usually those sold commercially contain beef, chicken, cheese or beans. But anyone can vary the theme, perhaps with spinach, gallo pinto, leftovers or even fish.
And then there are hundreds of possibilities for sauces, like chimichurri or other spicy types.
Although the empanadas displayed here are served intact, each can be cut open to allow a dash of guacamole, hot chile sauce and even lettuce and other salad fixings."