Practice before you teach
I have to agree with h2hoe below... the tutorial is rather solid in what it is demonstrating, but I'm getting the distinct impression that you don't really understand the _why_ of any of that.
That is, you could pick up an item, but there's no reference to how you can tell if an item has been picked up - say the item affects your movement speed, or you can't pass a certain point unless you're carrying a certain item.
For the record, moveSpeed is a variable, and it is basically being used so the speed of movement can be changed easily in one place - so left and right movement will stay the same.
To put together a really good tutorial, create a simple game... say you have to maneuver a character through a maze, and pick up a key to open the exit door... then the tutorial will take the viewer step-by-step through the creation of the game. That way, you and your viewers might get more understanding as to what certain techniques do, and where they might be applied. Future tutorials could expand on previous exercises, perhaps adding scrolling to the maze, or enemies and a health bar... the sky's the limit.
Don't take this the wrong way, this is all intended to be constructive criticism. Don't stop what you're doing, keep it up and keep it improving, and you'll do great!
Disclaimer: I'm a professional programmer by trade, but have never worked in flash.