You should consider forming an LLC (limited liability company) if you are concerned about personal exposure to lawsuits arising from your business. For example, if you decide to open a store-front business that deals directly with the public, you may worry that your commercial liability insurance won't fully protect your personal assets from potential slip-and-fall lawsuits or claims by your suppliers for unpaid bills. Running your business as an LLC may help you sleep better because it instantly gives you personal protection against these and other potential claims against your business.
Not all businesses can operate as LLCs, however. Businesses in the banking, trust, and insurance industry, for example, are typically prohibited from forming LLCs.