Books about Denali National Park are readily available at the visitor's centers at the park. I'd imagine many will also be available at many of the lodges and hotels in the area as well as at bookstores in Fairbanks and Anchorage.
Books:1. Wildflowers of Denali National Park by Verna E. Pratt and Frank G. Pratt, Alaskakrafts, Inc., Copyright 1993, ISBN 0-9623192-2-8.
In terms of ease of use, this book is probably the easiest to use when trying to identify common plants found within the national park. The plants are organized via color of the flowers, and is copiously illustrated with beautiful color plates of the most common species.
2. Plants of Denali National Park (North of the Alaska Range) by Camp Denali Publishing, Copyright 1981, Revised in 1986.
This is a checklist of the most common lower and higher plants found in the park to the north of the Alaska Range. It can be obtained at the visitor's centers in the park.
3. Flora of Alaska and Neighboring Territories (a Manual of the Vascular Plants) by Eric Hulten, Stanford University Press, Stanford, California ISBN 0-8047-0643-3.
This is a book more useful to serious botanists, although it is rather large for carrying into the field. It contains identification keys, line drawings and small range maps. It is probably most useful for trying to identify those species that are difficult to key out.
4. Flora of the Yukon Territory by William J. Cody, NRC Research Press, Ottawa 1996 ISBN 0-660-16406.
This book is also probably most useful to those who are serious botanists. It too contains identification keys and line drawings with brief descriptions of the plants.
5. Willows of Southcentral Alaska by Dominique M. Collet, Kenai Watershed Forum 2010. ISBN 97809822406-2-5
This is a useful book for those who have an interest in the willows of Alaska. The book has useable keys (for those used to willow terminology) and has a description page with nice watercolor illustrations of leaves and catkins. This is also available online in pdf format, as is a similar guide for willows of interior Alasak. See the willow page for these links.
6. Alaska Trees and Shrubs, Second Edition by Leslie A. Viereck and Elbert L. Little, Jr, Snowy Owl Book, University of Alaska Press, Fairbank, Alaska 2007 ISBN -13: 978-1889963-86-0
This is a great book for anyone with an interest in alaskan shrubs and trees. Nice descriptive keys are included to help distinguish between species within genera, and there is a page or two of descriptive details and line drawings for each species, including range maps.
7. Common Interior Alaska Cryptograms: Fungi, Lichenicolous Fungi, Lichenized Fungi, Slime Molds, Mosses & Liverworts by Gary A. Laursen & Rodney D. Seppelt, University of Alaska Press, Fairbanks, Alaska 2009 ISBN 978-1-60223058-3
Illustrated guide to a number of fungi, lichens, liverworts and mosses of interior Alaska, although it is not inclusive of all species found there. The book contains nice color photos, brief descriptions for the species covered.
8. Insects of south-central Alaska, by Dominique m. Collet, Kenai Watershed Forum 2008 ISBN 978-1-59433-074-2
A well illustrated booklet of common insects to be found in southcentral Alaska.
Denali National Park and Preserve
Alaska Wildflowers.us - Nice photos of Alaskan wildflowers, trees and shrubs with some history of botanical exploration of Alaska and the Yukon territories.
Camp Denali and North Face Lodge - World class lodging inside the park.
Consortium of Pacific Northwest Herbaria - I used the search function from this botanical website as one of my ways to determine which plant species are in Denali National Park and Preserve.
USDA PLANTS Database - One of the resources I use to update common and scientific names and synonymy for plant species. The Flora of North America website however uses more up to date terminology, although not all families are covered yet.
Flora of North America (www.eFloras.org) - For those with some botanical expertese, this website provides up to date taxonomic nomenclature and keys for identifying species, along with accepted common names and scientific synonyms plus species descriptions, habitat and ranges. Unfortunately, many of the plant families have not been included yet, although more are added each year.