Here are some resources that I’ve found helpful and inspiring.
John Holt was an educator in New York city, who coined the term ‘unschooling’. He wrote several books on the subject, based on his own years of observation of children in and out of school settings. These include How Children Fail (1964), How Children Learn (1967) and Learning All the Time (1989).
This site https://www.johnholtgws.com is dedicated to Holt’s work and includes the entire archive of the newsletter Holt founded, Growing Without Schooling, as well as writings by Holt’s long-time colleague, Patrick Farenga.
Sandra Dodd is a former teacher who unschooled her three children. She is a strong advocate for unschooling and her blog has tons of information for anyone looking to take this path or who is already on it. http://sandradodd.com/
Pam Laricchia is an unschooling advocate who hosts a weekly podcast and has written several books on unschooling. Her website has some insightful posts addressing many of the most common fears and issues that parents are likely to come across. https://livingjoyfully.ca/
https://suitable-education.uk is an interesting resource for anyone looking into self-directed education. It is UK-based and has a wide collection of articles, evidence-based research and personal stories about alternative education.