How to establish a publishing house

Hi,

one of my friend wants to establish a publishing house in Bangalore. I have no idea regarding this. I have the following questions-

How we can start it?

In which form we can start it?

 what are the legal formalities for that?

Do we need to get it register at anywhere or in any law?

What is the ISBN and how we can get it?

Please help me urgently. my e-mail id is cacssourabhjain @ gmail.com