Hi Raul. There are many business and fitness business books in the market for helping you with forms etc. Human Kinetics offers a number of selections related to the fitness industry and so this may be a great place to start.
As for building a name and reputation, I think that you’ve already taken a big step by participating in this forum. This is a great way to get other fitness professionals to recognize you, and for the general public to find your profile and answers. Keep up the good work, and continue to look for other professional sources in which you can participate and get your name out there (e.g. blogs, Facebook, other forums).