For those who know Swift, I suggest you go straight past the nitty gritty and download the repo here, get tutorial1.zip and start playing around with your custom sounds and code.
Note: I have started this tutorial with a playground file, but just a warning, it can be a bit buggy at times and you won't get all sounds playing immediately and will need to fiddle around until X-code gets it right. This behaviour does not occur when compiling into a mac OSX or IOS app, so I might also include some tutorials for creating your SceneKit scenes in both platforms.
Hope you enjoy, and leave some comments or contact me for any questions regarding this tutorial.
Keep Huscking (a concatenation of hacking and hustling).