Wisconsin's Department of Financial Institutions manages the registration of corporations in the state. The C corporation is the default form of corporation: unless the corporation makes an election to be treated as an S corp, it is automatically a C corp. A C corp gives owners limited liability, so you generally can lose only what you've put in. However, a C corp is subject to double taxation: the company pays the corporate tax and then any distributions to the shareholders are taxed on the dividend payments.
Check the Wisconsin database to make sure your company name isn't already in use. Your name must contain the word "corporation," "incorporated," "limited," or "company" or the abbreviation "corp.", "inc.", "co." or "ltd."
Complete the articles of incorporation for your C corp. The articles of incorporation must include the name of the corporation, how many shares the company can issue, the name and address of the registered agent, and the name, address and signature of each incorporator. If you want the corporation to start at a future date, rather than as soon as it is approved, specify the date you want the corporation to become active.
Mail the articles of incorporation, along with the filing fee, to Department of Financial Institutions, P.O. Box 7846, Madison WI, 53707-7846.