Put it in the Wiki
I realize this is the most obvious thing ever, but everywhere I have worked has had a huge knowledge base of tips, tricks, processes, etc and a meager wiki with sparse, outdated, or worse, useless information.
I have always been a champion of the wiki, and while a wiki can easily grow out of sync with the business, if you find yourself answering the same questions week after week, you need to document that somewhere, and a text document checked into code control doesn't count! Why not? You can't easily search across hundreds of text documents to find something, and if you are that tedious, then you also have to remember to update it before you search, otherwise you get stale information. And if you have that kind of free time and spare memory, you and I need to have a talk.
So, a wiki it is. It is always up to date, always on, accessable anywhere with internet. Brilliant.
And, most importantly, when someone asks me a familiar question, I simply tell them to Put It In The Wiki, because next time the first thing out of my mouth is Did You Check the Wiki?