This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
Simple .txt files have no nice features like formatting or password protection. You will need to wrap the file into a different format that does support password protection, and also use a program that understands it to read them again.