Do I need a professional license? Is a private certificate a license or do I have to go on to obtain a license too.
Yes, you need at least commercial pilot certificate to get paid. This is true no matter what you fly- from a Cessna 152 to a Boeing 747. A private certificate holder cannot receive compensation for flying per FAA regulations.
Re: "Professional"
The term is often used in job descriptions but means nothing in terms of FAA pilot certificates- and that is what they are although many still call them "licenses".
Re: Helicopters
I hope you have a VERY large sum of money saved up for this venture. Even the smallest rental helo like the R-22 runs about $175 per hour. I cannot imagine how much it would cost you to start your own helo business. Additionally, in all probability you will not be able to get insured as an owner operator with minimal experience.
I suggest you stop by Corporate Helicopters @ Montgomery Field. They can address your questions about helo training and I know they have hired on former students to do photo flights and tours.
http://www.corporatehelicopters.com/Here is another resource for you- "Pursuing a Career as a Professional Helicopter Pilot" here-
http://www.flymidwest.com/ProPilot.html
Flight Training Community 
Starting Out
