I'm not a guidebook kind of person, but I have to admit I use them as a general knowledge resource. I think this is really important, the background research that is. It allows you to arm yourself with useful knowledge with which you can begin to explore deeper into a culture.
A few months back I was invited to join a panel to discuss travel blogging. I met David Stanley, author of Moon Handbooks Fiji guide. He sent me a copy of his book and I gave it a go. First off I have to say that I am a sucker for organization, especially of thoughts, and David does a great job of organizing this book so that the monotony of guidebook reading is eliminated. He gives you numerous suggestions and a plethora of relevant information regardless if you are a backpacker or a resort junkie. David's book also addresses a pet peeve I have with guidebooks in general: GOOD RESOURCES. He provides you with relative resources, tons of websites and contacts.
So if you are thinking of going to Fiji, or the South Pacific in general, check out www.southpacific.org or pick up David's book at your local bookstore.