Below is a set of published articles I have written for examiner.com to help you kick-start your small business:
LLC vs. General Partnership vs. Sole Proprietorship
How to Instantly Obtain a Federal Employer Identification Number (FEIN) Online
How to Create a Vanity or Custom Facebook URL for your Fan or Business Page
In addition to the list above, in most states it is important to obtain your BOE (Board of Equalization) sellers permit. If you sell photography prints or make any sort of transaction through your business you must legally have a seller’s permit and pay sales taxes at the end of every calendar year. A nice benefit of having a seller’s permit it allows you to avoid paying sales tax on items that you directly use in your business including the non-payment of sales tax for your print products as well as other photography related material. In the state of California for example, the online link to fill out the form is here. Look for a similar site for your state.
Technically and legally you may be bound by the rules in your location to obtain a Business License. If you work from home like I do, you have to have a business license to work from home. This allows you to legally deduct expenses including home office, insurance, automobile and other expenses from your personal taxes. My advice is to find a great tax accountant and even a tax lawyer if you have questions.