Independent Scholar’s Handbook: How to Turn Your Interest in Any Subject into Expertise by Ronald Gross in 1993. Almost any book by Ronald Gross is useful.

Rethinking Careers, Rethinking Academia (Series):

Chasing Chickens: When Life After Higher Education Doesn’t go the Way You Planned by Rachel Neff in 2019.

Independent Scholars Meet the World: Expanding Academia Beyond the Academy in 2021