Why you need a website?
What is your purpose in having your business on the Internet? Because you think it is necessary for your business? Because everyone has website including your competitors?

What are you going to do with it?
It is necessary to define why you want to have a website and what are you going to use it for? Who is your target and what you want to tell them? What are you offering to your customer? What is the difference in what you are offering to your customer from what your competitors are offering?

The key elements
There are two important elements to create an effective website: content and design. It is important to have good content because if your visitors cannot find what they are looking for, they will leave your website forever and never come back. But if you have good content, they will come visit again. And it is also important to have good design because people can tell the difference between the website made by professionals and the one done by a beginners.