Before starting with the visual and technical design of your site you need to define the structure of your website. All the content and functionality needs to be structured in a suitable manner for your audience.
Create an information architecture based on product requirements, user needs and expectations, business goals and the available content. The combination of user, customer and content analysis will form the basis to create a suitable information architecture for your website.
Basic steps
Content analysis
In case of a redesign you analyze the current site and its content. When there is no site, you can read brochures, promotional material, reports of the company, gather content that will need to be presented on the site. if you have the time in combination with user research.
User & customer analysis
Gather as much info about the future users and/or customers. What are their needs, expectations, habits, etc.? Also try to find out about the environment and situations where the user will be when using your website. You can do this by talking to potential users and, if possible, observe them in action. Be aware to talk to the actual users and to their managers or marketing.
Some tips and tricks on creating an information architecture.
Ideally the IA process is the first thing you should do after a thorough process of user research. Also during the design phase and development it is necessary to do some checking.
The information architecture is the foundation of your website. Finding out after launching the site that the users cannot find their way in the structure will cause a structural problem and will cost much more in time and resources to solve it.