If you are using public transport then the easiest thing to do is to get a bus to Salobreña from Granada bus station. There are about 9 buses per day, the return bus fare costs 11.50. Most of the trips take around 1 hour. You can buy ticket on this site http://www.alsa.es It is also possible to get a bus to Nerja or Almuñecar but Salobreña is the nearest good beach.
In your own car you have a lot more possibilities. There is a fast highway down towards Motril and it takes about 50 minutes to get to the sea. Motril is not particularly interesting and it is better to go to one of the towns on the Costa Tropical such as Salobreña, Almuñecar, La Herradura or Nerja.
As an alternative to the fast motorway there is a very beautiful winding mountain road called the cabra (the goat) which goes down to Almuñecar. To get onto the road you have to follow the signpost to Otivar or Jete a few minutes out of Granada on the motorway.
Not many of the beaches have fine golden sand, most of the sand is grey grit and there is not much difference in sand quality along the Granada coast.
If you want a nudist beach the best one is Cantarrijan which is between Almuñecar and Nerja on the N340 it also has two good beach bars.
PLACES TO EAT:
(there are probably many more places than I mention here but these are places I have been to myself and liked)
In the old part of town near to the castle there is a restaurant called "El Peseta" it has a rooftop teraza with good views, simple Spanish food at a good price. The old part of town is an interesting place to wander around.
RESTAURANTE AVENIDA Lute y Jesús
An outside restaurant that does excellent fried fish and salad. It is very popular with the locals. In Avenida Europa. In the same stretch of road there is a good Pizza restaurant and some other eating places which look interesting.
As in most of the Spanish coast there are many places run by British people where you don't even have to order in Spanish. Examples of these are:
Lots of cheap lunchtime menus and British food. Not particularly high quality but good value for money nevertheless. Here you can see British football matches on Sky
Plaza de los Magnolios
If you want a friendly drinking bar where most people speak English try the RAGGED ROCK which is next to the big white cross on the headland in the middle of Almueñecar.
Beach bar (chiringito) Typical beach bar with good fish, pleasant waiters and good views of the sea.
This restaurant serves Paella and cooks the Paella in massive pans using wood as fuel.
They tried to overchange me once, I think it was an accident. The sand quality on this beach is good.
PLACES TO VISIT:
There are between 2500 3000 fish in total, with over 200 different species. There is also a very big tank which has a glass tunnel for viewing sharks etc at close range.
The Almuñécar Aquarium is at the Plaza de Kuwait, 300 metres from the Town Hall and Majuelo Park. At 14 euros a shot many people think it is too expensive, I had a very pleasant couple of hours there, it would he a good place to take kids.
THE NERJA CAVES:
(Cuevas de Nerja) Large underground cavern with stalegtites and stalegnites.