Business Model Builder, Start
If you have ever used other business modeling tools, this is going to be much easier; if you haven't, you will never want to. 
The Business Model Builder is a two-stage process that will help you identify the core components of your business and the connections / relationships between those components.  This knowledge will be invaluable as you evaluate your businesses future potential.  
Once you get started you can save and resume your work as needed, and if you get stuck or need some help you can invite people you know & trust to work with you can help complete the business model.  As you make progress, you may find that you have new insight or understanding about a portion of your business and you want to go back and change prior answers in the same stage you are currently in, no problem, just use the back button in the system to go back to your prior answers, and the rest of the system will adjust without having to redo other work. 
As you complete each stage you will get a confirmation of the work you just completed and a custom report showing your work that will be helpful as you analyse and refine your business.  After you pay for access to the Business Model Builder (below) you will be able to start Stage 1 right away.  Before you can move on to stage 2 take a minute and set up a member account with BPS ('Log In' icon top right) to get access to the second stage.  
If this is your first time creating a business model we know you may have a lot of questions; don't worry you will figure it out quickly.  If we could say two things to keep in mind they would be:  
1.  You can go back and redo your business model as many times as you need to; you don't have to get it perfect the first time.
2.  This is process in for your benefit and education, don't worry about right/wrong as long as you are learning because... see #1