Manuscripts to own and read
Both books are by Sheikh Abdul Basit Bayan and are read inside the Truth Geomancer app.
The Master of Geomancy, Volume 1 is the place to begin. It is the foundation text: the history of Ilm al-Raml, how to cast a chart by hand, and the sixteen figures with their elements.
Kanzul Mikban is the advanced companion. It assumes you already know how to cast a chart, and collects question-specific reading methods from the manuscript notebook.
New to the subject? Read the free Ilm al-Raml basics first. For the current price and how to get access, ask the author on WhatsApp from either book page.