To build, you need to include the following as libraries:
    bukkit.jar
    iConomy.jar
    permissions.jar

If you want helpful bukkit javadocs, you should get:
    the Bukkit source code

Once it builds, compress on linux using:
    jar or an equivalent archiver
      jenny:~/workspace/BetterShop/bin$ jar -cf BetterShop.jar *

or on Windows using:
    I have no clue. I guess something similar to jar.

And it's ready to be placed in a plugins directory :)