Paper wise aaplies to USA based biz:

Ensure your intended location can do biz as intended (IE ZONING)
Make your LLC,INC, ETC...
Registed the above with your state's secretary of state, aditionally some states require aditional submission if doing business in their state.
Then get your EIN # from irs (EIN is akin to a ssn)
Then get sales and use tax certificates, this varries from state to state.

The above is the minimum paperwork generally speaking you will need

~From an Anonymous Blogger~