Dalaman International Airport is a brand new showcase airport, used primarily for charter flights, but there are also good connections to main cities of Turkey.
Dalaman is the airport used for travellers to destinations like Fethiye (1 hour east), Ölüdeniz (1h20min east), Dalyan (30min west), Marmaris (1h30min west), Içmeler (1h40min west) and Turunç (2h west). Two more destinations may well use Dalaman, Kalkan (2h15min southeast) and Kaş (3h southeast), if they do not use Antalya Airport.
LookLex has no information about public transportation to and from the airport, taxis seem to be the only option. And they offer overpriced connections to Dalaman town, from where you can connect by bus to your next destination.
There are several companies offering car rentals from Dalaman, either organized at the spot or beforehand. As to what gives you the best price, there is no absolute. Out of high season, arriving in the middle of the day, you have a good chance at getting a nice discount. I pre-ordered here in May 2009, getting a brand new car at a great price from Pandora (Renault Symbol at €142 for a week all included).
Should you need accommodation before or after a flight, there are 3 hotels, the 3 star Burc and Dalaman Park, and the 4 star Therme Maris Spa. Use your search engine to make inquiries.
The airport has several tax free shops, alcohol, perfume and tobacco is reasonably priced. Others shops specialize in selling exactly what you just saw in the tourist bazaars but at inflated prices. Note that when you pay with credit card, the indicated prices in Euro are paid in Turkish lira, and at a slightly unfavourable exchange rate.
The nearest international airport west is at Bodrum, to the east it is Antalya.

Visit the website for Dalaman Airport.