Keep a track of the various festivals that take place in Spain - if you want to witness them, the list will help you plan; if not - it will help you plan your trip to avoid the crowds.
Siestas are a big deal in Spain and shops will remain closed every afternoon between 1-4 PM.
Pintxos are the best and most filling things to eat before a drink and will keep you full until dinner, which in Spain is usually late.
Spain is divided into various regions, all of which have a very distinct identity. Each region also follows a slightly different dialect of the Spanish language.
For travelling between the cities and towns of Spain, flights often work out much cheaper than trains.
For the bigger attractions, try to book tickets online to avoid the hassle of lines and the crowds.