Keeping your job is about more than just knowing how to perform and getting things done. You also have to keep working relationships in good standing order. There are many little mistakes that people make at work that can land them in hot water, or can cause them to be passed over when it comes time for promotions and raises. There are also bigger mistakes that can cost you your job. Be careful about keeping all things personal out of the work place, or you could be looking for a new work place soon enough. Office politics are more complicated than ever before.
Some companies have policies that working relationships should remain professional at all times. Dating those that you work with, and even worse, those that you work for can be grounds for dismissal. More and more companies today, however, are allowing dating of co-workers, but you still have to make sure your working relationships with everyone in your office are not mixing with your private ones. Don't guess about the policy where you work. Don't assume you know the policy or ask anyone not in human relations or in a position of authority. They could have bad information too. In some cases, they may give you bad information on purpose.
Working relationships can be ruined when you do something that may almost seem to be second nature to you. Gossip is something that most people do without thinking about in personal relationships. However, in working relationships, this can be disastrous. Spreading gossip about co-workers is going to make you bad, and could get them into trouble for no good reason. Bite your tongue and save the gossip for another time and place. Remember that gossip usually makes you look bad more so than the person being targeted by the rumors.
You may think that standing up to bullies at work could backfire, making you look like the troublemaker. This can happen, but if you want to enjoy good working relationships with your co-workers, you have to stop bullies from overwhelming you. Write down each and every thing that happens, and then when you have a good record of what is going on, talk to human relations or your boss. They can handle it privately and your other working relationships can be spared. Usually, these matters are taken care of in a way that will protect you. If you do not feel that is happening, continue to keep records of everything in the event you have to defend your position.
Besides these bigger issues, there are small things that can put working relationships on shaky ground. Never take anything from the break room refrigerator that is not yours. Never take credit for anything you have not done, and always fess up when you make a mistake. Always pay for your own lunch when out with coworkers, and accept an invitation once in a while, even if going out after work is the last thing you want to do. These things seem small, but they can make or break the best of working relationships.