If you wish to become an incorporated company in the United States, you have to file articles of incorporation, the equivalent of the UK's articles of association. These articles outline important things usually tied to your company's relationship with it's shareholders, and also what rights those shareholders have, among other things. More importantly, these articles establish your corporation in the U.S.
You file your articles of incorporation at your local secretary of state's office in the United States in much the same way that you file articles of organization for an LLC. The actual information your articles must contain may vary slightly from state to state, but you will always need to include some basic information about your corporation. For starters, you must list the name of your corporation and the address if it's primary place of business, even if it is run from a home office. Next, you must outline your corporation's primary function, be it sale of a product, the offer of some service, or some other type of business, you will need to be as clear as possible in your description. By not being crystal clear, you run the risk of limiting your company's activities. This comes from a tendency to word your corporation's activities poorly, so be sure to word it very clearly, this is a place where a business attorney's skill would be useful. After covering the purpose of your corporation, you need to list the name and contact information for your registered agent. This is an individual who can receive legal documents on your company's behalf. It is very important that this be a qualified person, who can represent your company with dignity, as well as uphold the ideals that you look to instill in the company.
Finally, but possibly most importantly, you have to list your company's stock information. Stock information includes things like the value of shares, information on transmission and transfer of shares, shareholder rights, and the amount of shares the company can and will issue. This information is crucial to your company's future, as it is what your shareholders will look at first. While all of this may seem daunting, there is help available to you. For starters, many states offer blank articles of incorporation, which outline the important information, and leave blanks for you to fill in. If you use these templates you can fill out your forms relatively quickly. Also, if you worry about whether or not you can effectively answer the questions on the forms, you can hire a business attorney for advice, help, and even to write the articles for you. Last but not least, the Internet is a great resource for any kind of information in regards to starting a business.