It's not an easy question at all and I've learned SO much the last couple of years since I thought about and then actually started my business. There's much more to it than meets the eye!
My local NAPO chapter is no longer functioning so I joined the San Francisco chapter which is fairly far away but has been really helpful. I get much more from that chapter than I get from the national group.
Having good relationships with other POs has been a huge help and I have two PO mentors who have been invaluable to my success.
A huge part of this business is education and knowledge of organizing concepts, products and ideas. The NAPO list servs (group email chats basically) have been fantastic for me.
I have taken tele-classes offered from some other POs that have been wonderful as well.
For those of you thinking about starting your biz and wondering if you should quit your job and jump in with both feet - I wouldn't. I did only because I was ready to leave my job anyway. Things are tough out there for most POs these days. Get everything set-up, get yourself a few clients and ease into it.