Of course, before you set out you'll need to know where you're going. Write to the Hawaii Geographic Society, P.O. Box 1698, Honolulu, HI 96806, and ask for their information packet. A good book on the subject, Hawaiian Hiking Trails, by Craig Chisholm, offers trail descriptions by someone who has been there. You can also contact the Sierra Club, Kauai Group, P.O. Box 3412, Lihue, Kauai, HI 96766. Any of the above will prove helpful to your planning.
Good maps are also necessary.
The University of Hawaii Press Reference Map of Kauai is available from the Hawaii Geographic Society and at bookstores on Kauai. Maps may also be obtained from the State Division of Forestry, P.O. Box 1671, Lihue, Kauai, HI 96766. There's a large swimming hole at the bottom. The trail begins off the Iliau Loop Trail. The trailhead is about a mile beyond the University of Hawaii Agricultural Experimental Station on Route 580.