When you have a job you dislike, you'll more than likely quit eventually. I say eventually because it's difficult to quit a job, but nobody really talks about how difficult it is.
There are a few things you have to consider when quitting a job, including having another job lined up before you quit so you aren't jobless. A few more things you should consider are: ample time for your employer to replace you, offering training, a letter of resignation and making sure you don't "burn any bridges."
You want to be sure that you give your employer plenty of time to replace you, if necessary. This is usually when you put in your "two weeks," but some places may require you to give a 30-day notice before you resign. Either way, it's also a good idea to offer to train your replacement, or at least offer help in one way or another. This just shows your employer that even though you're leaving, you're still willing to commit to the job you have now, and you're a good employee right up to the end.
When you do give your employer notice of your resignation, be sure you also type and print out a letter of resignation to hand to your employer in person, if able. However, you will also need to tell them in person that you plan on resigning from the position. The resignation letter just ensures that there is a hard copy of your notice so your boss will not be able to say that you didn't notify them with ample amount of time. Also be sure you scan a copy of the letter you will provide to your employer for your own files.
One of the most important things to remember when you resign from your current position is to not "burn bridges." You are quitting for a reason, and even if that reason is your boss or your manager, it's important to remain kind and professional towards them through this process and afterward. You never know when you will need a recommendation in the future.
Quitting your job can be scary, but sometimes it's very necessary to get to the job you want in life.