The Security book, or RuneScape Account Security, contains information on how players can protect their account.
A good password should be easily remembered by yourself but not easily guessed by anyone else.
Choose a password that has both letters and numbers in it for the best security but don't make it so hard that you'll forget it! Never write your password down or leave it in a text file on your computer, someone could find it easily!
Never tell anyone your password in RuneScape, not even a Moderator of any kind.
Ideally your recovery questions should be easy remembered by you but not guessable by anyone who may know you or given away in conversation. Choose things that do not change, like dates or names but don't choose obvious ones like your birthday and your sister or brother's name because lots of people will know that.
Other Security Tips
Bear in mind that recovery questions will take 14 days to become active after you have applied for them to be changed. This is to protect your account from hijackers who may change them.
Never give your password to ANYONE. This includes your friends, family and moderators in game.
Never leave you account logged on if you are away from the computer, it only takes 5 seconds to steal your account!
Stronghold of Security
Location: The Stronghold of Security, as we call it, is located under the village filled with Barbarians. It was found after they moved their mining operatios and a miner fell through. The Stronghold contains many challenges. Both for those who enjoy combat and those who enjoy challenges of the mind. This book will be very useful to you in your travels there.
You can find the Stronghold of Security by looking for a hole in the Barbarian Village. Be sure to take your combat equipment though!