I have a series I came up with a while ago, formulated from a suspenseful dream I had. Over time I developed the story into about six books (seven depending on how long the sixth is), each with their own adventure in which the MC goes off to recover a specific item, and most likely nearly get himself killed.

Anyway, the gist of the plot is a young boy named Chase, whose father has remarried (which Chase doesn't like), has been given the responsibility to recover six items, which eventually will take the shape of a sword. Chase takes on this task because his father (after miraculously showing up alive three days after he supposedly died in a terrible car accident during a storm) explains that the ones who saved him (they're complicated; they don't live in our world, but neither do they live in another world) told him about a man who is trying to, put simply, 'reinhabit' earth with his own people, because their world had been destroyed. That part is up for debate, to me it doesn't sound terribly creative.

So Chase goes off to find the six pieces using a magical key and a small chest. All Chase has to do is unlock and open the chest and he is taken to a different world, in which the piece is located. Sometimes he is accompanied by his step-sister, and once accompanied by his step-mother and a man who is looking after them (because his father isn't exactly alive, but not dead either, he can't stay with them. And the enemy can track him, so he doesn't want to endanger his family).

So, I planned in each book that Chase would locate and retrieve each item, on for each book. But I realized today that most if not all of them have very little plotline, very little action or anything. So here's where I need your help. Here is the basic rundown of each book, the settings are subject to change, suggestions for them are welcome:

Book 1:
Item- An arrowhead
Setting- A mainly wooded/grassy plain fantasy world.

Book 2:
Item- A willow bough
Setting- I was thinking a little villa by a lake that supplies my half-Elves with water. Or possibly the whole half-Elf city.

Book 3:
Item- 2 small diamonds (Yes, for now they will count as one item)
Setting- Originally, a store in our world. But now I'm thinking more of a beach resort-like place, in our world or in a fantasy world.

Book 4:
Item- Eagle's tail feather
Setting- A princess' palace and a rocky canyon/wasteland

Book 5:
Item- Dark red marble
Setting- A creepy, ghost inhabited funhouse world. Probably the better developed than all of them, or at least very close to developed.

Book 6:
Item- A lion's claw
Setting- Originally, the White House. But then I realized that might not be too realistic, so this one doesn't really have a setting.

Book seven would be the final enemy encounter and such (I won't spoil the ending;)). I am open to anything, even general plot ideas, characters, anything. This was based off a dream, and I've realized that if this series has a shot at getting published, it needs to be a lot more exciting than it is now.

I'll stop rambling now. Blowing things up is also a possibility.

I, too, struggle sometimes with having enough happen in a story. The worst case of this was my first, full-on win of nanowrimo. The story just sort of rambled on, I think I did a few good action scenes and such, but there was really no good plotline to it.
I think my idea is (if this will work for you) squish things a little more. Have him find a couple of the pieces in the first book, assemble the sword by the fourth book, and have a few other things he must do afterward before the final showdown. This would hopefully make more action (think about how quickly things moved in The Lion The Witch, and The Wardrobe). I don't know what/how you planned the finding of these pieces, but my suggestion (and something I, personally, would be interested in) would be to have some guardian over most of them. Say for the arrowhead, there is a hotshot warrior guy that owns it, and it has always hit it's target, therefore he won't let it go without a fight.
Another idea for the diamonds could be a dragon's hoard or coat (like smaug's armor that he had on his belly), but that's just a suggestion.
I guess I would just say try to make the pieces' environment naturally challenging (hard to find, hard to access, hard to kill), and have there be vigilant or unwitting guardians (like the lion claw could still be attached to the lion, making it quite a challenge to procure).

I hope this helped some. Anyway, God bless you as you try to make these stories work, and may you produce something that glorifies him!

Runningwolf- Ooh, guardians! I never thought of those. Those and a challenging environment would give it some excitement. You do have a point, making it a shorter series than a 6-7 book series. And it certainly would give it a fast pace.

Inesdar- I'll be sure to keep that in mind. I didn't know magical artifacts were stereotypical, but now I do! Giving charm to worlds is always fun. Characters shouldn't be too hard, as I have plans for them to grow in different ways (and Chase will be growing with each new item he retrieves, anyway)

I think I see. So I shouldn't spend too much time fussing over an outline and just write and see where it goes? (I gave up on an outline when the outline was beginning to look like a book in itself)

Glad I could help! Yeah, I think it's good to maybe write somewhat of an outline...and then ignore it if necessary. If you're writing the story, you should try to let it go where it goes...if that makes any sense.

It does. The outline for this series is really the only serious stab I made at making one, but I seem to get rather detailed. But letting it flow is what I prefer to do, before I lose enthusiasm to write.

Yeah! Last big story I wrote, I kept saying things without knowing what was going on, like one of my characters was having an extra hard time packing her backpack up a hill, and I thought: "that doesn't make any sense!" and went back to edit it out. But then instead I decided to find a reason she'd be having an extra hard time and found out that she had sneaked (snuked??) some of the heavy camping/survival equipment because she was pressuring herself to help my other main character, whom she could see was having a hard time as well. So I guess my point is that doing some things impromptu like that can be good too, although I might end up editing that later, it was more fun to try and figure why she was having a harder time than usual than to just decide she was doing fine and leave it at that. Have you ever done anything like that?

I'm sure I've had moments of "Wait, what?" about something and then try to untangle to snags. Usually I write things that make perfect sense to me, then someone will point that that doesn't quite make sense. It's a satisfiying feeling when you've figured it out, isn't it?

Yep! It goes a little like this: --> --> --> --> lol, but it's frustrating when that happens to a whole manuscript but hopefully that won't happen to me so much now. God bless!