Flight times to Spain from the UK are about two hours and leave from a wide choice of UK Airports. If you are planning on taking a driving tour you could take the overnight ferry from Plymouth or Portsmouth and wake up ready to start your holiday.
All the airports in Spain are served by public transport, with bus services at minimum. For the major destinations there are often trains or underground connections to the city as well. Of course, taxis and Spanish hire cars are available too.
Public transportation in Spain is good, with even the smaller destinations having good bus services. Major destinations have regular and cheap buses as well as trains, and Madrid, Barcelona and Valencia all have underground systems. Most cities have tourist buses which take circular routes stopping off at most of the main tourist sites. Taxis are strictly regulated so look out for a licence. Normally there will be a list of set destinations and prices posted inside the taxi too to ensure you aren't overcharged.
Travelling around Spain is pretty easy as there's a comprehensive public transport system. Spain has a high-speed rail network as well as slower services that will get you easily from city to city. There is also the option of intercity buses, and since routes can be run by more than one operator it's worth checking prices as they can vary wildly between carriers. Driving around is another option, and Spain has a good network of motorways, although some roads do have tolls. Ferries are available from Spain to Morocco, the Canary Islands and Ceuta, and there are a wide range of internal flights to make your journey around Spain as fast as possible.