via nolo
1. Don't tell off your boss and co-workers, even if you think they deserve it.
2. Don't damage company property or steal something.
3. Don't forget to ask for a reference.
4. Don't badmouth your employer or any of your co-workers to your replacement.
5. Don't badmouth your employer to a prospective employer when you go on a job interview.
via about.com
1: Don’t violate company policies
2: Don’t log instant messages
3: Use encryption for private communications
4: Don’t trust everything to encryption
5: Don’t bring your private encryption keys to work
6: Protect your private IM and e-mail passwords
7: Don’t store browser history or Web site passwords not directly related to work
8: Use encrypted proxies for private browsing
9: Don’t store the sole copy of anything important at work
10: Never give your employer reason to distrust you
via techrepublic