Madrid Dining and Food Guide
Eating in Madrid is usually very good. Once you're there, you'll realize many general differences between Madrid, Spain and US diets.
First, Spain eats a lot more seafood and pork versus the US. Also, they do not have as much beef as the US. Some people warn against eating the beef because it's different than US corn fed stock and people claim this can cause sickness. I did not experience this, but Take this into consideration when choosing your entres.
Other generalizations: Calimari is prevalent on menus, and when ordering potatoes, don't assume that you'll have ketchup. For water, you'll usually end up having to pay for a liter or 1.5L of agua mineral for your meal.
What are Tapas Bars?
Tapas are appetizers that come with drinks. In Madrid and the rest of Spain, there are many taverns devoted to serving tapas with alcoholic beverages. Tapas are an excellent value, and consist of a variety of foods - potatos, calimari, rice entres, seafood, and many other options.
Besids Tapas Bars, there are many other great dining options. Remember though, when sitting down to eat, the Spanish culture treats it as an event rather than "just eating." So budget an appropriate amount of time (hour atleast) when dining out at restaurants.