Computerworld has some career advice that applies to IT professionals as well as anyone else trying to avoid getting in trouble with the boss when making use of the office computer. To stay out of the doghouse and protect yourself, don't send inappropriate emails that might contain off-color jokes or hasty, insulting replies and don't even think of sending emails putting down co-workers. Be careful not to contradict your CIO in public, approaching him privately and quietly if you think he has made a mistake. And for goodness sake, don't commit social blunders at a company event, being sure not to drink too much or say something that will come back to bite you later. And if the job in your IT department becomes too much to take and you decide to jump ship, don't burn bridges.

For more details on office etiquette and common sense behavior:
- See this ComputerWeek article [1]