I think either you'll love Spanish food or you won't. That's just how it seemed to go with my American friends and myself in Spain. I personally loved it. One of my favorites was paella, a traditional Spanish dish of spiced rice, vegetables, and often either seafood, chicken, or other meats. Other excellent food there is the tortilla espanola, an omelete-like dish that is made of eggs, potatoes, onions and spices. Since I do not eat red meat, I didn't try any of the meat dishes in Spain, but they are really popular. Jamon serrano, a special type of ham, is extremely popular in Madrid and a popular menu item. Also, various types of soups are common, like gazpacho (a cold summer soup of tomato and spices), lentil soup, vegetable soup, fish soup, and more. One other note--bread is served with every meal, no exception! "Pan" is a basic component of the Spanish diet and you'll learn to love these huge bocadillo breads as part of your meal--trust me! Basically dishes made with olive oil, vegetables and meats are common.
As for drinks, the Spaniards love wines and in particular, Sangria, a drink made of wine and fruit juices-delicious. The cuisine is pretty varied, and you can find other types of ethnic foods around the city, but I would recommend finding a little Spanish restaurant with a "menu del dia" (menu of the day) for a real good Spanish meal.