I find a lot of people, as well as companies don't document their knowledge, or, do a poor job of it. I'd like to discuss what has been found to work well and not so well when it comes to doing this in the hope that we'll be able to assist one another.
I use Dokuwiki hosted on my webserver. My job requires me to be across a large range of topics, so having my notes easily accessible and available regardless of which PC I am using is extremely useful.
I have lost count of the number of times where I have documented something a few years ago which has come in handy later on down the track. The best thing is that as it is my own notes, I can write about certain "gotchas" which I encountered which I may forget some time in the future. On the other hand, Googling and bookmarks won't afford me this. Further to this, if I were to use bookmarks alone I run the risk of those websites not being around when I may need them in the years to come. There are the "archiving" websites, but I'd prefer not to have to rely on them if I didn't have to.
Having said the above, I'm definitely not against bookmarking. I have found a wiki entry with my own notes as well as useful external links to websites contained inside the wiki entry to be a killer combination. This way the information is all in one spot. If I'm worried about a useful website not being around when I need it, I use a HTML to PDF converter and attach it to the wiki too.
I have found File Syncing to be a huge benefit as well. There are multiple options out there, most of which are free. As I don't trust the cloud with my data, I use BoxCryptor to encrypt my filenames and files.
Using the above two solutions I have all of my notes and all of my files with me everywhere I go, regardless of which PC(s) I use.