Whether it is for your own curiosity or for a research project, there are plenty of online books about the history and celebrations of Halloween. The list of ebooks below are all online, can be read in your browser (no downloads), and they are completely free.
1. The Book of Hallowe’en by Ruth Edna Kelley
Published in 1919, The Book of Hallowe’en discusses the history of Halloween as well as folk beliefs and customs from around the world. It is a classic book on the subject.
http://www.gutenberg.org/files/20644/20644-h/20644-h.htm
2. Games for Hallow-e’en by Mary F. Blain
Another classic book on the subject of Halloween, published in 1912. It gives thorough instructions on how to throw a classic Halloween party.
http://www.gutenberg.org/files/5890/5890.txt
3. Halloween by Lillie Patterson
This is a children’s chapter book about Halloween’s history. Most pages contain illustrations and it can be adapted for home school use. Published in 1963.
https://catalog.hathitrust.org/Record/009911500
4. The Fairy and the Witch: An Allegorical Sketch for Hallowe’en by A.D. Nelson
A children’s Halloween play published in 1915.
https://catalog.hathitrust.org/Record/100406796
5. The Revel of the Goblins: For Hallowe’en or Any Other Time by Adelaide Westcott Hatch
Published in 1910, this is a children’s play.
https://catalog.hathitrust.org/Record/102114263
6. Hallowe’en Festivities by Stanley Schell
An all around Halloween book published in 1903. It contains games, recipes, ghost stories, poems, and entertainments.
https://catalog.hathitrust.org/Record/007591437
7. Hallowe’en Happenings by Lettie C. VanDerveer
This 1921 book is a book on setting up a spooky party, games and party tests, fortune telling, poetry, and ghost stories. Another classic among Halloween books.
https://catalog.hathitrust.org/Record/100326982
8. Highland Superstitions by Rev. Alexander MacGregor
While Halloween is not in the main title of this book, it is a classic and a general must-read for the season. Originally published in 1901, the full title of this book is Highland Superstitions: Connected with the Druids, Fairies, Witchcraft, Second Sight, Hallowe’en, Sacred Wells and Lochs, with Several Curious Instances of Highland Customs and Beliefs.
https://catalog.hathitrust.org/Record/001880523
9. The Evil Eye: An Account of this Ancient and Widespread Superstition by Frederick Elworthy
This book about the evil eye superstitions was originally published in 1895 and is considered a classic.
https://catalog.hathitrust.org/Record/000582867
10. Curiosities of Superstition by W.H. Davenport Adams
This book contains superstitions from around the world and has a chapter on Scottish Halloween superstitions. Published in 1882.