A Limited Liability Company helps to protect you, the individual, from being sued in your personal capacity or being liable for your business' debt. An idea can not be protected, but the actual products or services that you are going to sell can be protected by your LLC (debts and lawsuits arising from business matters).
The best time to form your LLC is before you start offering goods, products, and services for sale. Any "business deals" conducted outside of a Limited Liability Company, means that when something goes wrong, you will be sued for your personal assets.
Need assistance with forming your LLC? Belle Terre Law Firm, L.L.C. provides nationwide Limited Liability Company formations.