Driving in Spain is usually very easy, as long as you remember to drive on the right hand side of the road !
The Spanish rules and regulations change very often, to keep updated click on the following link:
n332.es Driving in Spain.
The most popular manoeuvres that seem to cause the majority of concern is how to enter and exit a roundabout, easy when you look it up on the n332 website which was created by a Spanish Guardia Civil Officer and a retired English Driving Instructor to help everyone understand the Laws of driving in Spain.