ALWAYS keep your originals, unless you have a very good reason not to! I can’t really think of any good reason not to, except for saving storage space. (Which is actually not a very good reason either. 🙂 )
I’m afraid I’m not a good example of how to organize files, @JamesStaddon is the one who is the model of perfection in that regard. 🙂
I’m quite sure he recommends organizing by date first, then subject. Something like this:
2016 > November > 2-Hay Ride
2016 > November > 6-Trip to PA State Capitol
2016 > November > 9-Joe’s 16th Birthday Party
And so on… I’ll let James give you all the details