When I read a book to learn I try read it more then once. It take multiple passes and multiple formats to learn material.
My methodology is this:
Read the book and highlight sections the are interesting or important.
After short period of time read it again taking notes.
Curate notes by removing or adding sections and updating the text. If a section is confusing or remains unclear, I refer back to the book and review it, updating my notes accordingly.
If the book contains examples. tutorials or practice problems then go back and do them. (Sometimes.)
Review the notes from time to time.
There is not enough hours in the day to do this for every book I read, but it is a habit I try to keep.