I've been on both sides of this topic. I'm just an amateur, so keep that in mind, but my typical workflow would be to take however many shots I feel are necessary at the time, go through them and mark the ones I really like, go through those and mark the images from that group that truly stand out, and then from those, pick 1-2 images from each "scene" that truly tell the story I'm trying to tell of that shoot.
Shooting other people's pictures and doing this is a lot easier. When I'm shooting pictures of, say, my kids at the beach on a special trip, it's a lot harder to delete the "less spectacular" images because they're still a memory. Now... sure, the out of focus images and whatnot I'll toss aside, but I may keep a "B roll" of images that aren't as aesthetically pleasing as my A-list images, maybe not the ones I'd print in a photo book, but they're still special memories.
The upside to the photo hoarding is when you come across a situation later in life that causes you to want to go back and find those B or C roll images. For example, my dad passed away unexpectedly at the end of 2012, and in going back to search for images of my dad with the family, I had found that there were some I had taken that were just casual informal shots of "people doing stuff" he was in. I had not marked them as ideal images because at the time I was post-processing the event they weren't the focus, but I was certainly glad I had the shots to go back to.
If I were recommending a post-processing data management workflow to a beginner, I'd recommend the A and B roll philosophy. Drill a shoot down to the best of the best and keep the "story" of the shoot crisp and clean, otherwise you'll bore your subjects; at the same time, keep a B roll of the really good (or sentimental but technically inferior) shots, maybe exported as jpg's or uploaded to a photo site or something. Discard the rest.
As far as portfolios or what you share with people (whether it's professionally or amateur) again I'd say: keep it clean and tell the story. It's unorganized and unseemly, IMO, to share out albums that are overflowing with images or repeat a theme needlessly.