The capital of Sardinia si the city of Cagliari - as most of Europe's big cities, Cagliari has its own international airport called Cagliari-Elmas and is one of the three airports of Sardinia, the other two being Alghero Airport and Olbia - Costa Smeralda Airport.
Another way to get to Sardinia is on water, by ferry. There are several Mediterranean Sea Ports in Sardinia, where you can get a ferry: Porto Torres, Olbia Isola Bianca, Golfo Aranci, Arbatax, Santa Teresa di gallura, Port of Palau and The Port of Cagliari. From here you have national (travel between Italy mainland and Sardinia) and International ferry cruises to countries like Spain, France, Malta or Greece or to Islands like Mallorca or Corsica. Italian tourists prefer to use the ferry to travel to the island. There are no highways in Sardinia, but the road infrastructure is ensured by express-roads which connect all large cities and resorts of Sardinia.
If you decided to travel to Sardinia by ferry, have a look at the following websites of Ferry Cruises Companies, in order to plan in advance your cruise:
Another interesting but effective way to get to Sardinia is by using the trainferry service. Sardinia has a very developed railway network which is connected by the one on the mainland Italy, through the ferry service.
A lot of tourists use "Trenino Verde" as a way of transportation through the Island. The train travels with low speed but it goes through the most wild parts of Sardinia, letting you discover magnificent views on the way.Website Trenino Verde