Before you even start submitting resumes and searching for a new job, think about what it would take for you to financially leave your current company. Do you have savings and/or a rainy day fund that would provide you with float during times you aren’t receiving a paycheck? Savings are a buffer between you making sound, reasoned choices or choices made out of desperation. It's advisable to have three to eight months of salary equivalent saved up, to give you the cushion needed to survive until the next job.
Determine what you need to survive by comparing your total expenses to your net income. Include important bills including rent, mortgage, utilities, tuition, groceries, auto insurance, credit card bill(s) and car payments. Do you have enough in savings or a rainy day fund to sustain your lifestyle for a minimum of three months? Consider all expenses when measuring your income (or savings) versus expenses. This includes recreation such as dining out, clothing and movies and gas money. Look at your credit card balance. Your credit card isn't an option when you're not employed because there won't be income to pay off what you add to it. Can you pay it down to nothing now and only use it for items that are paid off within the no-interest payment period? This is a noose-around-your-neck that you must take care of above all. If you live paycheck to paycheck, obviously you will need to make sure you have a “sure thing” lined up in terms of another job before telling your boss to take this job and shove it. If you aren't saving already, start now. The sooner you do, the sooner you can fulfill the dream of quitting your current job.