Nearly all visitors arrive by air at Nadi International Airport (NAN) on the west coast of Viti Levu. This is where you should fly into regardless of where you're headed — it has far more international routes and cheaper fares than Suva's Nausori Airport.
Fiji Airways operates the most routes, with direct flights from Los Angeles, San Francisco, and Honolulu in North America, and from Sydney, Melbourne, Brisbane, and Adelaide in Australia. Qantas and Virgin Australia also fly from Australia. From Auckland the flight takes about three hours; from Sydney, around four; from Los Angeles, about ten.
Citizens of Australia, New Zealand, the US, UK, Canada, and most EU countries receive a free four-month visitor permit on arrival. Your passport must be valid for at least six months beyond your planned departure date. Check current requirements with the Fiji Immigration Department if you're unsure — visa rules do change.