This was Schultz's downfall - after all, an entire radio audience heard him call fellow pundit Laura Ingraham a "right-wing slut." On the clock, never let yourself be overheard insulting or calling coworkers derogatory names. Neither should you put these things in writing - after all, text can be saved and shared. Part of creating a professional image is biting your tongue, even when you're about to blow a gasket. If you need to address an upsetting issue, do it with civility and relative calm.
"I don't know..." or "I'm new!"
If you've ever been curbed by a cop and tried the "but I didn't KNOW I was doing 60 in a 45!" excuse, you know it's not, in fact, an excuse. The same principle applies at work. If you're unfamiliar with a task or practice, admit it, but don't just leave it at that. Instead, say something along the lines of "Actually, I've never done this before. Would you mind taking a second to show me how?" Turn your lack of knowledge into a chance to be proactive and show your interest in learning and succeeding.
"That's beneath me."
As an office newbie, you should be willing to do anything - as long as it doesn't bend your morals or ethics. Even if you feel like you're doing bitch work, keep in mind that the little tasks are often the most significant, and the ones that will serve you best as you move up the chain. This sound ridiculous, but after my recent promotion, I found that most of my new coworkers had no idea how to print labels on our office printers. They have to ask others to do it for them. I, however, get to save time and effort because I can do it myself. So doing even the smallest tasks can have some future benefit.
"Oh my gosh, this weekend I was SO drunk, and I hooked up with this random dude, and..."
TMI is a major problem at work, especially in an environment where clients/customers might be around or where your workspace is a cube basically separated from your coworkers by a fuzzy piece of plywood. Yikes. So, if you don't want your boss to know about your boyfriend's sex faux pas, to suffer a passing customer to hear your irritation with a dumb relative, or to force a subordinate coworker to hear you yelling at a customer service rep over the phone, please keep your personal conversations off the clock.