The 18th edition of Patent It Yourself is a thorough step-by-step instruction manual that starts with questions for evaluating the viability of an idea all the way to submitting an patent application. For readers focused on the application process my recommendation is to read and study those chapters for a week or so, then set it aside for several days before reviewing the relevant chapters and creating a rough draft. If there's an application deadline involved, allowing a least two weeks for rewrites, revisions, and followup questions to the USPTO was very helpful for me.
Some passages are still confusing despite the authors' best efforts to simply lawyer-speak into layperson's language, but there are many examples provided to help with clarification.