If you have children visiting or staying with family members (such as grandparents), make sure the family members know your rules concerning technology that your kids must follow. Just because your kids leave the house does not mean the rules about what they can do online change.
Source: SANS Security Awareness

One of the most effective ways you can protect your computer at home is to make sure both the operating system and your applications are patched and updated. Enable automatic updating whenever possible.
Source: SANS Security Awareness

A password is only as secure as the computer or network it is used on. As such, never log in to a sensitive account from a public computer, such as computers in a cyber cafe, hotel lobby or conference hall. Bad guys target public computers such as these and infect them on purpose. The moment you type your password on an infected computer, these cyber criminals can harvest your passwords. If you have no choice but to use a public computer, change your password at the next available opportunity you have access to a trusted computer.