Change your password often using the passwd command. It should not be a name of a person, your own name, a word in the dictionary or anything that can be easily guessed by anyone who knows you. This is very important! Our systems are on the Internet, a global network of computer systems, and there are people out there who try to break in by guessing passwords. Choosing a bad password doesn't just compromise your account, it increases the vulnerability of the entire system.
A few tips for picking a good password: try using numbers, upper and lower case letters and punctuation, in combination. Avoid words or names (or backwards words or names), in any language. Avoid personal data (like your phone number or your license plate). Don't use UNIX or DOS commands. Don't use any word that appears in the output of 'finger'. Instead, try using the first letter or two of each word in a phrase, throwing in punctuation and numbers to taste. Be creative!
Some examples (please don't actually use any of these examples; try to think of your own that are like them):
"9 dollars and 8 cents is Too Much" 9$&8ciTM "I want a 7 caret diamond" Iwa7^<> "The sharp lawyer was called to the bar" T#lwc2t| "the times they are a-changing" t**taa-c "They cried Liberty! Equality! Fraternity!" TcL!=!F! "Dashing through the snow" -ththsn
Do not tell anyone else your password. Do not write it down anywhere.
Your account is for your use only, per the conditions on the account form.