Get a good attorney with expertise in business law (in your field, ideally), and get a good accountant. Then involve them heavily as you proceed with your startup. Take their advice seriously. They are subject matter experts.
Those two things are not optional. Both of them will be more aware of all the thousands of gotchas than you are, and can help guide and protect you.
Those two things are not optional. Both of them will be more aware of all the thousands of gotchas than you are, and can help guide and protect you.