Here is the process I go through to get scales under my fingers so I can execute them rapidly. For a great book on scales and other saxophone fundamentals, I recommend Larry Teal’s The Saxophonist’s Workbook: A Handbook of Basic Fundamentals. But one caveat: Don’t read scales from a book. I know that seems like I just contradicted myself, but what I mean is there are good scale-based exercises in that book. But once you know how a major, minor (harmonic, melodic, natural, Dorian, etc) is constructed, you’re not doing yourself any favors reading it.