No matter how great your idea is, most people expect that you have it written down. When I was new to inventing, I had no idea what that meant. I searched around but didn't find any universal format for documenting my ideas.
Location: Writing down the location of your business is very important. Locations with greater customer traffic usually cost more to buy or rent, but they require less spending for advertising to attract customers. This is especially true of retail businesses where traffic count and accessibility are critical.
You have to do research and you have to put your thought in to it. You have to follow a certain format that will put everything in perspective. Luckily enough, you can find business plans examples or even templates if you just know where to look.
For an online business, a detailed and in depth business plan is usually not necessary unless you are trying to combine your online business with a traditional business. For most online business startups, the detail involved with planning a traditional business is not required. However, it would still be beneficial to you if most of the topics were still covered, even if only briefly. Having a written plan in front of you will help you to focus on important aspects of the business.