As New York Small Business Law blog says, "Articles on choice of business entity are a dime a dozen." But I agree this article concerning Choice of Entity from the worldwide law firm of O’Melveney & Myers is an excellent guide.
The article contains the answers to many of the frequently asked questions concerning using a "C" corporation, an "S" corporation or an LLC/Partnership for business operations. The article discusses the tax aspects of the various entities. The tax treatment of your business should be a major factor in determining which business entity you choose. I also recommend speaking with your accountant before you make a decision on which entity to use.