I attended a fantastic presentation by Dan Wells, at a writers conference back in February on story structure.
If you 're great at characterization, but struggle at weaving a compelling storyline together, this should be helpful. He refers to it as The Seven Point System. Before you start putting this structure together, you at least need to know who the main characters are, what the setting is, and what the major conflict is. Once you have those, start plugging in the rest as follows:
2. Plot Turn 1
3. Pinch 1
5. Pinch 2
6. Plot Turn 2
Of course there can be several more pinches added, or even plot turns, but this is the basic structure--and it works. Sometimes it helps to start backwards.
The Resolution. Everything in your story should be leading up to this moment. What is your protagonist trying to overcome? Is it an external thing, force, etc, an internal thing, perhaps a combination of both?
The Hook. What is the hook that will grab your readers on page 1 or at the very least in chapter one and keep them turning the pages? Sometimes you have to use the ice-monster approach (think Star Wars, Empire Strikes Back where the movie begins with Luke being attacked by an ice-monster). Starting your novel with a lot of boring background / back story information is a big no, no - - especially if you're trying to get published for the first time. Dive right into the story and sink a hook into their reader that they can't escape from.
The midpoint is that magical place in your story where your protagonist finally begins to move from a reactionary state to one of action and determination (think Lord of the Rings and the Council of Elrond - when they finally decide what to do with the ring). It doesn't mean conflict and turmoil is over, it just means they're finally starting that journey towards resolution.
Plot Turn 1, is what moves you from the beginning to the midpoint. Major conflict is introduced, the protagonist’s world changes, etc. (think about Luke coming back and finding his Uncle dead or Harry Potter learning that a world of magic exists and he's a part of it)
Plot Turn 2, (can you guess?) moves the story from midpoint to resolution--where your protagonist receives that final thing needed to make it happen (think Neo, "The Power is in you!" or Dorothy in Wizard of Oz when she realizes all she has to do is click her heels or Luke: "Use the force Luke!")
Pinch 1, is where conflict is introduced--and the pressure is applied to your protagonist. Could be a bad guy attacks, a sickness, a death, etc--something that forces your character to action (think Harry Potter - when they discover a troll in the bathroom and no adults are around to help).
Pinch 2, apply more pressure until the situation feels hopeless--like there is no way to escape, at least until you get to plot turn 2-- starting to make sense? (think about when Gandalf appears to have been killed by the fiery demon from hell)
This structure can be used for the Hero's journey, romance, tragedy, etc. - - don't feel constrained by genre. As you work through this, make sure your protagonist goes through the try/fail cycles (at least twice). This can be done through multiple pinches where it doesn't always work out in the protagonist's favor. Victory should always be earned - - keep building the overall tension to the resolution with a few small victories along the way. Spread out the action to keep good pacing (your beta readers can help you with that).
Last of all, remember, this is a structure and is not a replacement for good writing. It helps if you take this and break down an existing book/movie as an example. Give it a try with Avatar and see what you come up with. The format works on just about any well written novel/script.