Titles are in rough chronological order and order of importance. If you are interested in purchasing the first three, you might try contacting the Wabaunsee County Museum. If they are sold out, keep an eye out on eBay. Sometimes used booksellers (like AbeBooks) have them for sale, although they can be pricey.

1901 Early History of Wabaunsee County with Stories of Pioneer Days and Glimpses of our Western Border by Matt Thomson
  The first Wabaunsee County history printed on the local level (Matt Thomson was publisher of one of the Alma newspapers). "Containing Portraits and Biographical Sketches, Historical Reminiscences, Views of Towns, Street Scenes, Public Buildings and Private Residences, Our Churches and School Houses, Election Returns and Notes, Newspaper History, G.A.R. Notes, a Short Criminal Record, &tc." The book was reprinted in the early 1970s by Robert Stuewe, then owner of the Alma Signal-Enterprise.
Online Index
Biographies | General Index | Illustrations (Portraits) A-M N-Z | Illustrations (Churches)
Illustrations (School Houses) | Illustrations (Hotels) | Illustrations (Residences)
Illustrations (Misc.) | Unclassified
1976 New Branches from Old Trees: A New History of Wabaunsee County by the Wabaunsee County Historical Society
  At just over 900 pages, New Branches from Old Trees was the first publication by the Wabaunsee County Historical Society. It includes a cemetery index (which has since been updated, see 2000's Stories of the Past), township histories, church histories and submitted family histories. The family histories are indexed by township below. The Topeka and Shawnee County Public Library has a full name index to the book available in their genealogy room.
2000 Stories of the Past: the Third Edition of Wabaunsee County History by the Wabaunsee County Historical Society
  This is a fantastic book that updates and improves upon the 1976 New Branches. There are over 500 biographies, plus new school, church and town histories. The book also updates the cemetery index originally compiled and published in 1976.
Online Index
Biographies: A-F | G-K | L-R | S-Z | Miscellaneous Stories
1883 History of the State of Kansas by William G. Cutler; first published in 1883 by A. T. Andreas, Chicago, IL.
  This book contains information on the entire state, but there's a good chapter on Wabaunsee County. Topics include location, population schedules, early settlers, county organization, Civil War information, schools, churches and biographical sketches. The entire book has been transcribed and is available online at the Kansas Collection website.
Online Index
1907 Business Directory and History of Wabaunsee County by the Kansas Directory Company of Topeka, Kansas

This is a great snapshot of the businesses of Wabaunsee County in the early 20th century. Topics include county history, organizations, schools, Civil War records, stock business, floods and much more. This book has been transcribed and is available online at the Kansas State Library (Blue Skyways) website.

This book is also online at GoogleBooks in digital format (online or PDF download).

1976 Pioneers of the Bluestem Prairie: Kansas counties Clay, Geary, Marshall, Pottawatomie, Riley, Wabaunsee and Washington by the Riley County Genealogical Society, Manhattan, Kansas
  Includes a brief history with biographical sketches of the pioneers and early prominent citizens of each county.
various The Kansas State Historical Society has compiled a list of county related books on their website.
1990s In the late '90s, the Topeka Genealogical Society published three books of great interest to Wabaunsee County researchers: Wabaunsee Co., Cemeteries vol 1; Wabaunsee Co, Selected Obituaries & Vital Records (deaths) 1892-1911 vol 2; and Wabaunsee Co., Index to 1919 Atlas.
  The three books can be purchased from the TGS on their website.
1961, 1974 Maple Hill Stories - by Roderick Turnbull. A well written book containing stories of Maple Hill pioneers covering social life and customs. In 1974 there was a followup book, More Maple Hill Stories.
1915 Reminiscences of the Early Settlement of Dragoon Creek, Wabaunsee County, Kansas - by Stephen Jackson Spear. Don't know much about this book... it may be from an old Annals of the Kansas State Historical Society.
other The Kansas Collection - a wonderful website with a number of transcribed books on Kansas and Kansas History. Carrie, a full text online library, is similar, but has a broader range of books.
various There are also a handful of compiled genealogies written by individuals and submitted to the local libraries. Please see the Research section for a list of repositories.
various Area historical and genealogical societies frequently publish monthly or quarterly magazines. These magazines sometimes publish record indexes for Wabaunsee County that may not be found anywhere else. You can check with the societies directly or PERSI (for more information, see the public library section under Where to Research).