steve004 said  What methods do others here use?

  

The old-fashioned method–I write it down.  The trick is to remember where the note can easily be found, so I usually write it somewhere in a book on that subject, either on the end papers or in the margin of a relevant page.  If the info. is too long to copy out by hand, I’ll copy it with my printer, then file that copy in the most logical book.  I have also “bookmarked” many pages on different websites, but it that site “dies,” as they sometimes do, the info is of course lost.