Bukkit

Installation is pretty standard, just copy 'Planetoids.jar' to your plugins folder where you run CraftBukkit, and make sure you're using the correct version of CraftBukkit. If you downloaded the zip file, it includes a default config.yml, which needs to go in plugins/Planetoids/config.yml.

Starting for the first time

If you're letting Planetoids generate its own world (which is the default, and is what you should be doing if you're not using a multi-world plugin), the first time you start it you should see something similar to this on your console:

Before the worlds are loaded/generated, you should see the standard loading messages for Planetoids:
[INFO] [Planetoids] Loading Planetoids v1.4.0
[INFO] [Planetoids] Enabling Planetoids v1.4.0
[INFO] Planetoids version 1.4.0 is enabled!

After that, other plugins and the standard worlds will be loaded. Once the server is done loading, Planetoids will create its world and initialize it, you should see something like this:
[INFO] Done (3.898s)! For help, type "help" or "?"
[INFO] Preparing start region for level 3 (Seed: 0)
[INFO] Made new system with 550 planetoids.
[INFO] Preparing spawn area for Planetoids, 4%
[INFO] Preparing spawn area for Planetoids, 24%
[INFO] Preparing spawn area for Planetoids, 93%

After that, the Planetoids world will be ready to go! Log in and type '/pltp', and you should teleport to the Planetoids world. Keep in mind that it may take a few seconds for your server to generate the area after you teleport in, and it will look like you're falling through a grey sky while that happens. You shouldn't be losing any health, though, and after a few moments you'll appear on the default leaf shell/log core Planetoid.

Using with multi-world plugins

The only change you need to make in Planetoids to use it with a multi-world plugin is to set autocreateworld to false in config.yml. When that is disabled, Planetoids will not create a world by itself, and you can follow the directions from your multi-world plugin to use Planetoids with it.

If for some reason your multi-world plugin needs the name of the generator class rather than the name of the plugin, it is called 'PGChunkGenerator'.

The following config.yml settings will only work on the automatically created world:

planetoids.worldname
planetoids.alwaysnight
planetoids.weather
planetoids.commands.pltp (this should be set to FALSE when using multi-world plugins anyway)
planetoids.disablemonsters
planetoids.disableanimals

You'll have to look at the settings for your multi-world plugin to see how you can accomplish these in your other custom worlds.