Should I put my investing business in an LLC, S corp or C corp

[Debbie Camara]

My family and I are just starting out in real estate investing and I have been reading a lot of forums and watching webinars. I have read that you would want to put your business in an LLC. But then I also read about S corp and C corp, how do you know which one is best? Also, must it be set up before any investments are made or can it be done at anytime?