I would recommend two. F# in Action [1] by Isaac Abraham is a great (and recent) introduction to the F# language. For a more philosophical, domain-oriented book, you can't go wrong with Scott Wlaschin's Domain Modeling Made Functional book[2]. Scott's blog[3] is also must-read material.

[1] https://www.manning.com/books/f-sharp-in-action

[2] https://pragprog.com/titles/swdddf/domain-modeling-made-func...

[3] https://fsharpforfunandprofit.com/