A couple years ago I stumbled across Microsoft OneNote, which is probably the best utility for this kind of thing that I've ever come across. Since moving to Linux at home, though, I've had a hard time matching it. You could try Kbasket, which is the closest I could find. I've not extensively tested it, but it seems like it's up to the task. I only mention OneNote specifically for something to use as a search query for Linux equivalents since I haven't looked around for these in a while.
At any rate, it's a virtual scrapbook. It's completely searchable, and you don't have to worry about formatting and such (unless you really want to!). It's integrated into the shell and you can just take screen grabs, paste them in, copy text right in, move hyperlinks right in - basically anything you want to keep record of, can easily be written in there.
At work, I've found this software absolutely indispensable!