Which state are you from? If you are in New Jersey, you can visit this website http://http://www.state.nj.us/njbusiness/index.shtml here you can find a guide to permits/licenses required to do business in new jersey.
I hope this helps!
Your Practical Admin
Not all types of businesses require licenses, it depends on your state's requirements. Go to their dept. of commerce website (google it) and find out. Find out if you have obligations to pay Sales Tax on any of your sales or services.
If you are an LLC or some sort of partnership then what the business makes will probably be considered your personal income. I would wait until you actually make a profit, then be aware that you need to pay taxes on your income. The IRS has a good small business section that will advise you on much of this. Be aware that they do not like to wait for their money so if you are making a profit, and believe you will end the year with a profit, then you should be paying quarterly estimated taxes. They will not let you slide by for more than a year or so if you continually end up owing a chunk of taxes.