Good security depends on good passwords.
Good passwords are hard to guess, so they must not be simple words or well known names, either yours, your pets, or your children.
They should have a mix of upper/lower case letters, numbers and special characters. (&@^$%) Remember that there are always hackers out there guessing passwords. If they guess yours, they will send out thousands of emails in your name before we even know it happened.
Be careful out there.