When looking for a hostel... make sure to book hostels that have, a common room, guest kitchen, internet access, and NO CURFEW! you dont want to be locked out of your hostel and 1 in the morning.
When in Spain, do as the Spaniards do and TAKE A SIESTA. Spanish people stay out until AT LEAST 5 in the morning. Your going to need that hour or 2 of rest between 3 and 5 in the afternoon.