Novels are funny things. If you do it just right, your readers will be hooked from the opening line. They'll continue reading just to find out what happens next. And they'll even forgive those minor errors that all writers make from time to time. But if you do it wrong, you'll find that your readers not only put down what they're reading, but they won't pick up something with your name on it ever again. And that was your career as a writer.
One of the ways to grab and keep a reader is by understanding the traditional arc of the story. Now, I'm not advocating that you adhere to this arc. But you should be aware of what it looks like so that you'll be able to tinker with the arc as you see fit. You don't want to be too traditional, after all. It could bore the readers you're trying in engage.
The arc of the story can be seen as an inverted "V" that's a little lopsided. You typically start your novel with your main character doing something that he or she does every day. Then something happens to disrupt that. Perhaps it's a result of something the character does or maybe it's some outside influence. Whatever. Something has to happen (unless you're writing a "Day in the Life" kind of story, which I personally find a little boring). So, something happens to disrupt the equilibrium and something has to be done to solve the problem that's cropped up. And so begins your arc, your climb up the long side of the inverted "V."
If you're writing a novel, you'll probably have to throw in a few more obstacles. Just one probably can't sustain the entire novel. A short story may only need a single obstacle. Regardless of how many problems you introduce to your plot, they eventually come to a head, to a climax, to use the common term.
After the climax comes the little bit of wrapping up that's necessary to most plots. Here you'll often find emotional resolutions, people settling down, and just a general calm feeling. Unless it's part of a series, in which case you'll probably have to leave an opening for something else to happen (otherwise, what's the point of writing a series of novels).
This is just a very basic idea of the action in the story. Sometimes the action will be action/adventure related and sometimes it will be more emotional, but there's always something that needs resolving in a novel. That's what brings in readers. Play with this arc until you have something that will work for your story. But always write with your readers in mind.
