Scrivener probably doesn't require a textbook, just the included tutorial (and videos provided on the site), but to make certain I'm Writing and not constantly trying to figure out the writing software, I've opted for getting the printed how-to book.
Haven't started yet as I'm still doing one more read through on SUNDARK, An Elle Black Penny Dread before it heads to my beta-reader (then back to me, then to the editor). But I'll be needing those 'cork boards' and ability to archive all my research links, soon. Dark Victorian: EVERLIFE, the third in my Gothic steampunk series is, like BONES, carrying a few subplots--and new secondary characters.
BONES was nearly a mess working in Word's linear manner. I had a few fits. But I got through it and am very eager to use Scrivener's option for moving all manner of story bits around and keeping character names and place names on hand. THAT will save so much time and hair-pulling.
And who knows, perhaps Scrivener will also make it easy for me to work on 3 manuscripts at once. I'm asking a lot, but that would be very cool. :D
YOu can download a free trial or just buy the very affordable software, here: https://www.literatureandlatte.com/