I went to Fiji as a stopover on the way back fron New Zealand back in 1997. We stayed at a resort called "The Hideaway". We landed at the airport later at night, and drove in a rickety taxi 1.5 hours on what is basically a narrow dirt road until we finally arrived at the resort (ps - make sure you negotiate the fare first). The accommodations were interesting as instead of a hotel, you stay in a "hut" or bure with no a/c and litle bug or pest control, except for the complimentary can of bug spray they leave on the bathroom counter for you.
I remember walking into my room at around midnight completely exhausted and being attacked by a flying cockroach upon entering the bathroom.
The food in Fiji was, for the most part, some of the worst I have ever had. Breakfast was always good, and safe - so I would load up in the morning. Dinner was interesting to say the least. I remember ordering chicken one night and getting something that had a vertibrae... not sure what that was.
On the positive side, I have never been anywhere as beautiful as Fiji. We were there in January and the water was very warm. It was also a very deep blue - so blue that it was green. Snorkling was amazing - as there was a wide variety of very colorful fish to look at.
For a day trip, we did something called a "3 Island Cruise" where they took us out on what looked like a pirate ship to 3 small islands off the coast. One island was tiny - you could walk from one end to the other in 30 seconds - it was pretty cool. One of the other islands was the home of another resort, which was also very cool.
For another day trip we took a taxi into Nadi (where the airport is) and did some shopping. There were a number of stores there with clothing priced very cheap with designer labels - I suspect they were knock offs. Definately be ready to bargain with the vendors.
Anyways... enjoy your trip. There is certainly lots to see and do... and don't forget to try the Kava