I recommend checking out Jim's writing blog if you haven't already. He offers some great advice.
Also check out this guy's website:
http://johndbrown.com/John Brown's an up and coming author and I've actually corresponded a few times with him via email. He's really nice and offered some great advice. I'll sum up the most import thing I learned from him. Broken down in its simplest form a story starts off with a problem. A big gnarly problem that the character wants to solve. If it's something that the character can solve easily in one fell swoop then it's not a good problem and not worth writing about.
So your story needs to focus on a problem that puts a lot at stake for your main character.
If you're having problems getting your character from point A to point Z, consider mapping out the stoyline with an outline of the scenes you want to include. I've found it helpful to break down scenes something like this:
Scenes start with a problem that the character wants to solve. The problem can be summed up in a yes/no question. The answer is always "Yes, but..." or "No. Futhermore..."
IE "Will the hero kill the monster that lives in the cave?"
One possibility: Yes, but he got bitten by the monster and now he has 3 days to find an antidote or he'll turn into a monster.
Another possibilty: No the hero fails to slay the monster. Futhermore, in attempting to do so woke up a dozen of its brothers and now they're all going to swarm across the countryside raising chaos. Uh oh.
After the scene comes the sequel. The sequel generally doesn't involve conflict but it gives the characters time to react to what's happened, allows the readers to follow the character's train of thought, and allows you, as the writer, to point your protagonist in the right direction.
So let's say the hero goes to the tavern to drink and mill over his problem. "Okay, the monsters are going to raid the countryside. I'll hire a mercenary crew to help me. But where will I get the money?" The character overhears some people complaining about how the crooked mayor raised taxes for the fourth time this year. Chatting with the other patrons leads the character to find out that the mayor has been lining his own pockets with this money. He decides that his conscious will allow him to rob the mayor to get the money to hire this mercenary crew to slay the monsters.
This sets up your next scene. Will the hero succeed in getting the money to hire this mercenary crew to hunt down these slobbering monsters that're running amuck? Let's go with the "yes, but…" clause. Yes, but the mayor finds out and is pissed and has put a bounty on his head.
So, in addition to having to worry about these monsters running amuck, the character has to watch his back because hired assassins will be after him.
And you can keep building from there, constantly giving the character more problems to try and solve as he gradually plods his way along to the big showdown at the climax.
Okay I'm painting with broad strokes here, and these examples are cheesy but what I'm getting at is that you want to do your best as a writer to keep your characters in hot water. Conflict is what excites a reader. Problems cause conflict. So as your character goes off to solve this major problem that is the crux of the story he or she should encounter trials and tribulations that you can build scenes around. You can use these scenes and sequels as building blocks to get to this big climax that you've got planned.
Scene = problem in the form of a question, always answered as "yes, but…" or "no, furthermore…"
Sequel = reaction and goal for the next scene.
Now, keep in mind there is no scientific formula to writing. But I think you'll find this conflict cycle to be a useful tool, especially if you're not sure where to take the story. Just remember that whenever you're stuck, just think of ways to make things harder or more perilous for your protagonists.
I hope this was helpful. Good luck!