Guest Contributor Lara White wrote a nice piece on digital-photography-school.com about the merits of not only editing and evaluating your images, but actually selecting the best and deleting the rest.
(Click Here) to read the original article on digital-photography-school.com
Lara suggests that we should "be ruthless" in deciding which images to keep, and which to throw away. She makes several points regarding why this is a good practice, including that making decisions makes us learn what's right and wrong with each image, that it allows our truly great shots to stand out without being surrounded by average ones, and that over time it teaches us which perspectives and compositions work.
I found Lara's examples - a ho-hum shot of a dessert table, and a smashing closeup of a single dessert (image above) useful. I think it reinforces the idea that simple is better, and reminds me of one of my own faults - trying to tell the whole story in one picture. Sometimes that's just not effective, or even possible.
There is one other benefit to ruthlessly deleting everything but our best work, and that is storage space (and associated access time). Not only do hard drives fill up fast, it takes a finite amount of effort to find those best shots again, when they're surrounded by marginal ones in the directory. Yes, Lightroom's flags and selection tools make this easier, but it can never be easier than not having the clutter there in the first place.
The only downside I can see is that we may inadvertently delete images that will become important to us later. I think that's pretty rare.
Something good to consider when thinking about your workflow.