Are there any good scripting tutorials that you could recommend? Ideally that cover how to add one to game objects in the CK...
Thanks for all the help guys!

To add a script to a base object (or a reference object already in a cell), open it up in an editor window and look for a section labeled "scripts", and click the "add" button in that section. If that field doesn't exist, you can't attach a script to that kind of base object. If you're adding a new script, select "[new script]" in the window that pops up, then enter a name for your script, otherwise filter for the name of the script you want to attach. For a new script, the "extends" field will automatically be set to what it needs to be for a script attached to that kind of object (though you can extend scripts of your own that extend that type of script), but pay attention to what you are extending as it will determine the kinds of functions and events you'll have access to.
After you enter your script name and select OK, you'll get dumped back to the editor window. Right click your newly attached script and either select "edit source" or "open in external editor".
Look for the kind of script you are extending in the links at the bottom of http://www.creationkit.com/Category:Papyrus (i.e. "MiscObject" or "ActiveMagicEffect", etc.) and it'll tell you what functions and events you have access to within your script. You also have access to anything present in parent types, so check out the parent as well (i.e. "MiscObject" extends "Form", so you get access to all of Form's goodies in a MiscObject script.)
Spells themselves can't have scripts attached, but they can have script type effects added to them (create a script archetype magic effect with your script attached, and add that effect to your spell.) The amount of information available to ActiveMagicEffect scripts ( the ones attached to Magic Effects) is abysmal though. Hopefully SKSE will be able to help out with that in the future.