https://www.amazon.com/Focused-Fearless-Meditators-States-Cl...
https://www.amazon.com/Right-Concentration-Practical-Guide-J...
https://www.amazon.com/Mindfulness-Bliss-Beyond-Meditators-H...
The author is both a long term meditator and used to be a neuroscience professor. The book teaches meditation in a stage by stage way which is very easy to follow.
Another excellent book is "Mindfulness, Bliss, and Beyond: A Meditator's Handbook" (https://www.amazon.com/Mindfulness-Bliss-Beyond-Meditators-H...).
1. https://www.amazon.co.uk/Right-Concentration-Practical-Guide...
2. https://www.amazon.co.uk/Mindfulness-Bliss-Beyond-Meditators...
Leigh Brasington reports that people he's spoken to who have studied kundalini yoga say the strong piti of the first jhana is the same as awakening the kundalini, so there's a bit of an "all roads lead to Rome" about these practices, which is encouraging.
Both authors are on dharmaseed. Worth checking them out. They're both great teachers.