Well, any answer is going to be very opinion based since there isn't a single answer. It depends on how you like to work and what you are used to.
Personally, I've ended up almost exclusively using Microsoft OneNote as it is flexible, quick and easy to use. All my notes and most of my links go into notebooks that I reorganise from time-to-time based on what is of interest.
I've used many other knowledge management tools in the past but they never really help in the long-term for me. OneNote with it's comprehensive searching along with some simple organisation into Notebooks, sections pages/sub-pages is enough. You can take hand-written notes via a tablet too and it will generally still search the text. Same for documents, voice and video recordings embedded.
I use a personal list of sites and blogs that I consume via RSS. Articles of particular interest are pushed to OneNote (or may just be kept as an interesting link with a comment). Finding trustworthy sites with reliable sources and writers is key.
Twitter might be useful though I tend only to publish curated links and comments to it, I rarely find the time to consume via Twitter. I suspect the trick is in finding the right voices on Twitter that publish a high enough content-to-noise ratio. Finding the right hashtags can also help.
Whatever you do, don't forget to record the source not just the content so that you can reference it in the future. Also, don't be afraid to both regularly reorganise your knowledge but also to archive it by starting a new notebook - possibly from scratch or only copying over some key info. Keep the old notebook in case you want to reference it.