One important thing to note as an entrepreneur is that you should always Pay your bills!
In your business you will have money flowing through your bank account, but it is not ALL your money. It belongs to your vendors, your employees and other stakeholders like government. The money is also meant to cover other expenses the business will have. If you start spending money allocated, you will find yourself in deep trouble, and probably lose the business. Make sure that employees and vendors are paid first. One of the reasons for business failure is personal use of business funds.
Also, many businesses fail to make enough provision for funds that will drive the business to breakeven. Often money is raised to cover capital expense such as machinery, outlets etc. The business is strangled as there is no sufficient money to cover day to day operation.