Ok, lets say I am going to start up a record label, and it will be called ABC records. What are all the legal things I need before I can put things out under this ABC label ?
It's a business like any other. See your state regulations for setting up a corporation and go at it.
(Talk to other people who have small businesses in your area --- you're not going to believe all the red tape and hassles you're getting yourself into setting up a small business. Hope you have a good bank account!!!)