Describe what you are going to do, and the need you percieve for it, the area you are going to do it in etc.How you are going to do it and what resources you are going to need, then do some financials, so many customers at so much and a projected turnover and growth.
Most plans i've seen ask questions and your answers build the picture.They are only essential if you want to be successful, but if you have little interest they probably won't help.A lot of people who scoff at them and do succeed have one in their heads.
Not many people make a lot of money by accident, you have to plan for it.