I downloaded the JAR and placed it in my server's plugin folder, but when I went to implement it, all the imports could not be found. My compiler says "package net.milkbowl.vault.chat does not exist"! Am I suposed to use a vault library or something?

sounds like you are having issues setting up your IDE properly, not sure I'll be able to help you out with that.

Am I suposed to do more than just drop the JAR in my plugins folder?
EDIT: That is, if I want to use the vault API?
EDIT: I just noticed that I was suposed to add depend: [Vault] to my plugin.yml file. That is very likely the problem... can you explain more about what that means?

By the way... this is my current plugin.yml. Am I doing it right?

name: MageCraft

author: Lightning_11 (Owner)

main: com.javaminecraft.CasterMain

commands:
    Target:
        description: (Unused) Set your next spell's target
        usage: /Target <Player>
    Spell:
        description: Cast a spell
        usage: /Spell [SpellLevel/Highest]
    Tome:
        description: Help on magic
        usage: /Tomb [Info Type]
    Dimentions:
        description: Tests to see if the world dimention variables are set
        usage: /Dimentions
    Shop:
        description: Open an NPC shop for the closest player
        usage: /Shop <Shop Name> <x> <y> <z>
    Test:
        description: Used by staff to test new features
        usage: /Test

depend: plugins.Vault

version: Alfa 23

Oops, my mistake. Sorry for closing the issue. I didn't mean too.

Ok... Let me restate this. So far, I want to use the vault API, so I put the vault.jar in my server's plugin folder. Then I tried to use the API, but the files that need to be imported to not exist on my computer. Do I deed to download these?
Next, I found that I had to put depend: [Vault] but I don't really know what that means. I guessed (see above) but my guess must have been wrong, because it caused an error that crashed the program. Does anyone have any idea what I am doing wrong?

EDIT: I downloaded the master-vault file and am trying to find it in my editor

@Lightning11wins - this is much beyond what I can help you with on the issue tracker for Vault. I suggest going onto the Spigot forums or Bukkit forums and requesting help on how to setup a development environment and dealing with java libraries, or looking for tutorials that describe this process.

Ok... I just though you would know what depends: [vault] meant

@Lightning11wins - that means the plugin depends on vault.

What do you mean by that... It will not run if vault is not already running?