Here is a list of classic (mostly 19th century) books about the Froebel Kindergarten method which have been scanned into PDF format. Click the title to open/download the PDF. You may also be interested in the currently published book Inventing Kindergarten.
The Pedagogics of the Kindergarten by Friedrich Froebel edited/translated by Josephine Jarvis
The Kindergarten Building Gifts by Elizabeth Harrison & Belle Woodson
The Kindergarten Guide: vol. 1 - The Gifts by Maria Kraus-Boelte & John Kraus
The Paradise of Childhood by Edward Wiebe
Daily Program of Gift & Occupation Work by Carolyn S. Bailey, Clara M. Lewis
Froebel's Gifts by Kate Douglas Wiggin & Nora Archibald Smith
Froebel's Gifts [plain text] by Kate Douglas Wiggin & Nora Archibald Smith
Froebel's Occupations by Kate Douglas Wiggin & Nora Archibald Smith
Home Occupations for Boys and Girls by Bertha Johnston & Fanny Chapin
The Psychology of Froebel's Play-Gifts by Denton J. Snider
Symbolic Education by Susan Blow
The Third & Last Volume of Friedrich Froebel's Pedagogics of the Kindergarten by Josephine Jarvis