Fiction books that are already published make great textbooks - because that book in your hand has been deemed worthy of publication - so it has something going for it.
For the mechanics of the story: One of the fun ways I have found to improve my writing and pull together stories or novel ideas is to take a favorite book and analyze it. Get your favorite book from a used book service and mark the heck out of it. Mark at what page you are into the story and don't want to put the book up. Mark when the store reveals itself, when does it resolve, etc.
From this you can draw a rough outline that will tell you the construction of this particular author's work. From this you can create your own, and decide what you want and when you want it in the story. Plus it is a lot of fun.
Plot: what kind of books do you like? What will you pick up off the shelf and not put down? Start small with some free writing. Just create a scene: maybe a woman standing at the kitchen sink watching her kids leave for school. What does the kitchen look like and what is this woman like. Ideas will begin to pop into your head. Sometimes the characters write the stories for us.