Allow me to introduce you to my new favorite organizing tool - Evernote!
Being a visual/kinesthetic learner, I'm terrible at keeping information in my head. It all has to be written down if I want to find it/remember it again. Pinterest has been a God-send for me, because it lets me organize huge chunks of my life via pictures - quick and easy to reference and keep straight.
But Pinterest has its limits. Being image based means that it won't sort, track or help with anything not image-based. It also won't differentiate between parts of a page. So if you only want a portion of a given webpage, trying to copy it into a pin can be messy and inconvenient.
Evernote is to words what Pinterest is to images. Users can create "notes" (the equivalent of a pin on Pinterest) containing everything from a few words to an entire document. You title the note whatever makes sense to you and save it to a "notebook" (the equivalent of a Pinterest board). It is then accessible from anywhere you have internet, and fully searchable. This has been a God-send to me in tracking information and resources related to grants I'm working on; now I can keep those highly polished "blurbs" that can be reused/recycled from app to app in one central location and find them in seconds!
Although I haven't used it yet, Evernote also has a people-tracking option that looks like it would be amazing for anyone whose job requires a lot of networking or people management. You can keep all your info on your contacts in one place (accessible from your laptop or smartphone) for quick reference. Business cards can be scanned in, meetings/calls can be tracked - all kinds of neat options!
Evernote is free, and versatile. It's proving to be a great tool for me. If you're a visual learner or need to handle extensive amounts of documents or word-based information, I recommend checking it out.
What online tools have you found most helpful?