So you are ready to take the leap. You are ready to quit. I know it has been a long time, but what does your contract say? Do you have to give your employer a certain amount of time? Is there a noncompete clause that may prevent you from moving forward with your next venture? Read carefully. For the large print giveth, and the small print taketh away.
Pay down credit cards so that you are not carrying balances. Know your monthly expenses. Trim unnecessary expenses. Contact all three credit bureaus and address any issues with your credit report. For costs formerly handled by your employer, like health insurance and retirement savings, consider how you will handle those costs going forward.
Conventional wisdom previously called for six months living expenses for savings. However, if you are starting a business, you should also set aside at least one quarter worth of business expenses.
If possible, secure another source of income before leaving your current job.