Tapas are a wide variety of appetizers, or snacks, in Spanish cuisine. They may be cold (such as mixed olives and cheese) or warm (such as chopitos, which are battered, fried baby squid). In select bars in Spain, tapas have evolved into an entire, and sometimes sophisticated, cuisine. In Spain, patrons of tapas can order many different tapas and combine them to make a full meal. In some Latin American countries, such snacks are known as bocas.
The serving of tapas is designed to encourage conversation because people are not so focused upon eating an entire meal that is set before them. Also, in some countries it is customary for diners to stand and move about while eating tapas.
My own tip : If you visit Barcelona, there is a restaurant name La Esquinica,they served pretty good Tapas, and the owner is a old friendly man. :) Let me know if you go to Barcelona, I may have some tips for you :)
And if you want to learn how to make some tapas, i will give you a tip in another day when i have free time