Guidebooks 

The Ultimate Kauai Guidebook; Hawaii The Big Island Revealed; Maui Revealed; Oahu Revealed ALL by  Wizard Publications, Inc.  These books are controversial, as some people disapprove of the fact  that these books have sometimes recommended hiking trails on private land, and places sacred to native Hawaiians. The books have some good information and some which should be disregarded. If in doubt about whether access or hiking is legal and permitted, don't do it. 

Trailblazer Travel Books: Kauai Trailblazer, Maui Trailblazer, Oahu Trailblazer, Hawaii the Big Island Trailblazer, No Worries Hawaii
The activities in these guides appeal to a wide range of levels, from family strollers to full-on adventure hikers. They are arranged geographically by trailheads and include the length of each hike and the elevation along with historical background, scenic highlights, maps, photos and highway navigation. Directions to beaches, rainforests, waterfalls, coastal bluffs, whale-watching perches, volcanic craters and historical sites make it easy for visitors to design their own itinerary and maximize their vacation time. Photos from their current Hawaii adventures can be seen at www.trailblazerhawaii.com.

Perfect Hawaii Vacation Guidebook  This free on line digital flip book differentiates between the four counties in island state of Hawaii, Kauai, Oahu, Maui and Hawaii, aka, the Big Island.  Included are beautiful maps, videos and photos.  Each Island tab brings you to that island and describes the "must do" activities.   by Toni Marie Davis ( Executive Director for the past 13 years of the Activities & Attractions Association of Hawaii, Inc.) 

Frommers Hawaii 2006 , by Jeanette Foster

Lonely Planet Hawai' i:  The Big Island , by Luci Yamamoto

Schmap Big Island Guide , a free digital guidebook

Literature

Letters from Hawaii by Mark Twain.  Not Mark Twain's best book, but it is quite interesting to see how people got around the islands in the 1860s. Twain wrote these letters as a correspondent for a Sacramento newspaper. At times humorous and at times overwrought, it's a worthwhile read for those of you embracing part of your inner nerd.

Hotel Honolulu by Paul Theroux.  While Theroux does write some fantastic non-fiction travelogues, this book is a novel. Incredibly creative. It is definitely R-rated with some over-the-top sexual passages. The main character becomes the manager of a hotel on Waikiki, and the book covers all the eccentric characters he encounters. You meet the whole range of humanity in this novel. Very funny. The book also does a fine job of highlighting some noteworthy quirks about modern-day Hawaiian culture--in particular, that uniquely Hawaiian vocabulary. The best part is: after reading this book, you'll be much more in tune with the lingo in "The Descendants". Highly recommended!