http://forum.virtualtourist.com/discussion-338181-1-1-Travel-1-178-Spain-discussion.html
The above is a link to a discussion on a trip from Malaga to Alhambra. The most important thing is to buy you entry tickets in advance or you won't get in.

they put 2000 tickets on sale every day, the tickets are for specific times of the day to control the number of visitors at any given time. BUT they start selling them at 8am and people start queueing very early for them. Last week some guests of ours arrived at the Alhambra at 7.45am and got tickets for 4pm, so if you want to go early under your own steam then that is an alternative.
Other guests have gone on the coach trips, very early start as the bus picks up all along the coast before heading to Granada but at least entry is guaranteed.
All of the guests who have been say it is definitely worth the trouble.

My Dad went last week To Alhambra and Granada, he used a tour company that is opposite the Bali hotel (Benalmadena) think he paid 40 euros a person and that included a midday meal, pick up time was 7 am and he was dropped back at 7pm, he was very pleased with the tour and the guide was very informative.

The Alhambra is definitely worth going to see but you can book in advance either over the Net or by telephone. Don't ask me why but this is done via the BBVA bank and you'll find details at:

http://www.alhambradegranada.org/guias/alhambraEntradas_en.asp

along with a link to the BBVA booking site.

Your ticket gives you entrance to the gardens etc for the whole of the day but will give you a specific 30 minute slot for gaining entry to the Palace bulidngs. Once in, you can take as long as you like going round but if you miss your slot then they won't let you into the Palace. You should allow at least half a day, possibly longer if a keen gardener but it will be worth planning to spend as long a day as possible in Granada - it's a beautiful city with a lot to do and see apart from the Alhambra.

SM