i just got back from spain 3 nights ago and tvlleerad on my own. If you need info on trains and bus schedules, you can check renfe.es, alsa.es or pesa.net It really depends on the cities you want to visit as different buses and trains operate different routes. From Lisbon, you might want to pass by Salamanca as it is on the way from the Extremadura region. Lisbon and Valencia are too far apart. you might want to fly to Valencia instead of travelling by surface. Chech spanair.com I think spending 3 nights in a place won't make your trip too hectic.