I recently got a copy of the book "How to start a home based business for dummies" And it really has been helping me out. You can go to Barnes&Noble.com and get it used for very cheap. I would imagine you DO need a license, and LLC might be the best way to go, so if someone rams your taxi with an old woman in it and her next hurts she can sue YOU. With a Sole Proprietorship you would be liable for her injuries (or "injuries.") I would talk with a local small business attorney in your area and ask them what to do. They would know best.
      Answer1:LLC are always safe, you never know what can happen.