I used to keep a huge Notepad .txt file of a ton of company knowledge, gotchas, offhand documentation, and any kind of tidbit that I might need later. A few years ago, I migrated all of this to OneNote with detailed, formatted notebooks for every broad subject I could categorize. I recently shared my OneNote notebook with guys relatively new to my team, and I found them using it all_the_time. So not only is the "Knowledge Log" good for you, it can also be a useful tool to help others on your team.