Just the usual.... work out a business plan after you've found out exactly what people will be willing to pay you for any screen printing you do.... only then will you know what sort of screen printing you need to be doing and in what quantities etc...
Then talk to your local business bank manager or other business adviser maybe an accountant (spit!) and see if its feasible, if not forget it!!
John.
__________________
A little knowledge is a dangerous thing - Googling is far worse!