Marbella has everything I have been looking for in a European beach vacation. It's an area with loads of natural beauty from the beaches to the Andulalucian mountains. We stayed at the Parque Apartments which is within a very short walking distance to the beach, restaurants, shops and bars. No need to get a taxi, but they are readily available and inexpensive. I highly recommend the Parque Apts or the Skol for location and convenience. The team at the Skol, (Tracey, Ann, Paul and Neal), helped us recover our luggage and made us feel like family. They even got a birthday cake for me! I booked our apartment though Des at Homeaway from Home. Highly recommend him and the site.
The Old Town is a short distance from the Parque and you can easily walk the paseo maritime (the prom) to get there. I don't recommend eating in the center square of the Old Town, as it is touristy and overpriced. You can do better elsewhere such as one of the many little restaurants dotting the beach below the promenade. You can have really fresh grilled sardines, turbot, baby squid, sole, etc., for a very reasonble price. La Red is terrific and always crowded. Fish is grilled right on the beach and can't get much better. In the French Riveria, you would pay five times as much. There are also numerous tapas bars on the stroll to the Old Town, which you can sample as you start your evening. We normally at dinner around 10:00 or so. Then maybe gelato and a night cap around 2:00.
As far as the beaches, they are mainly grainy sand and the water is swimmable - the tide won['t kill you and there aren't too many rocks. Two chaise lounges and an umbrella cost about 5 euros, which is not bad. There are beach hawkers selling jewelry, clothes and knockoff purses. They can be a bit persistant, but they do have nice cheapy gifts to take back. I got 2 really cute necklaces for gifts (1 for me) for about $10.00 USD. There are also unlicensed Asian girls offering foot massages, etc. starting at about 15 euros. Beware they will run if the beach cop is nearby, but the girls are just trying to make a living, so I didn[t have problem getting a foot massage.
It would be helpful and courteous to brush up on your Spanish since some shops etc., only speak it. The people are pleasant, fun, upbeat and really energetic. The service is amazing anywhere you go. It can be hectic, but since the Spanish economy is so bad, everyone works as hard as possible.
I can't say enough about Marbella. Let's put it this way, we are going back next year. I will not, nor do I recommend going through Charles de Gaulle, unless you feel like missing your flight or having numerous delays. It's just too big and I have been stranded there consistently, but, I digress.