Quitting is permanently and voluntarily leaving a job. Unless you have another job lined up (written job offer in hand that you have officially accepted), quitting is not usually good career or financial move.
Do not quit a job based on a verbal offer. Get the new job offer in writing, first.
Exceptions exist, of course. If continuing to do your current job involves you in potentially illegal activity or if you feel your life, health, or safety are at risk, then quitting may be your only - and your best - option.
However, typically it is not a good idea to quit one job before you have landed the next one.
Two primary reasons:
So, if you can avoid it, don't quit one job before you find a replacement.
People do lose their jobs when their employers discovers that they are job hunting - not 100% of the time, to be sure, but often enough to make searching from home and being careful at work a very wise strategy. These days LinkedIn makes it much easier to conduct a stealth job search, so be sure to have a 100% complete LinkedIn profile.
Even though employers prefer job seekers who are currently employed, most of them view one of their own employees who is job hunting as "disloyal" or a "risk" to the organization. They fear that customer lists or product secrets or something critical will be stolen by the departing employee and given to the new employer, possibly a competitor.
Often, your current employer's competitors could be your next employer. But, proceed cautiously when contacting and interviewing with these potential employers. It is possible that they might be interested in you only for information they could get from you about your current employer - a big risk for you.
See Job-Hunt's Guide to a Stealth Job Search for suggestions on how to keep your job search a secret from your current employer.
What if you've already quit your job?
Hopefully you quit for a really good reason, not because you were angry with someone or embarrassed about something. So, time to move on. Your will get a new job, and the best way - by far - is to network your way to that next job. Networking beats resume distribution, even online, much more than half the time (networking works 80% of the time according to the experts). See Job-Hunt's Guide to Job-Search Networking section for more information.
Online job search expert Susan P. Joyce has been observing the online job search world and teaching online job search skills since 1995. A veteran of the United States Marine Corps and a recent Visiting Scholar at the MIT Sloan School of Management, Susan is a two-time layoff “graduate” who has worked in human resources at Harvard University and in a compensation consulting firm. Since 1998, Susan has been editor and publisher of Job-Hunt.org. Follow Susan on Twitter at @jobhuntorg and on Facebook, LinkedIn, and Google+.