You know, it all depends on what you want and need when you say "organize".
I spent a lot of years happily using "whatever", in other words whatever was free or at least cheap and easy to use.
As my photo library grew, though, it began to dawn on me that those tools might not be the best tools, and that my approach may not have been so effective.
It was during that period that a book came out, "The DAM Book", addressing Digital Asset Management (DAM) and that got my attention, since the book took DAM seriously, addressing several aspects and proposing a "comprehensive" solution!
Well, it was also during that time that some software developers were actually discussing comprehensive solutions. One proposed solution that "popped to the surface" was that Adobe was working on a product which they dubbed Lightroom, one which would combine the essentials of photo processing with extensive DAM functions as well as good output functions.
Apple at the same time was working in a similar direction with their Aperture app.
And so, Lightroom and Aperture were "birthed".
Since I'm not a Mac user Aperture was not an option (and neither is iPhoto), but Lightroom soon became my "go to" app for all my DAM work, most of my photo processing, and most of my output.
But I'm not saying that those "serious" apps are for everyone...you need to take your time and check out your options!