A limited-liability company ("LLC") is commonly referred to as a "hybrid" business structure, meaning that it shares characteristics of both a corporation and a sole proprietorship. It allows its owners to insulate themselves from personal liability for business debts, does not require the payment of separate business taxes (the tax "passes through" to its owners), allows for a great deal of flexibility with regards to its organizational structure, and is subject to fewer regulations and restrictions than are other types of business structures. Establishing such a company in Wisconsin is a rather straightforward process.
Where the equipment you use in your business was acquired as a gift, you may report your estimate of its current market value on the Business Property Statement (that is, what you think it would sell for in the open market place). Enter that estimated value in the most current year's cost line and add a note indicating that the entry is an estimate.