Ask your customers before you build a new website
The one thing I find companies miss in getting the web design process underway are the opinions of their customers.
Design, navigation, content, SEO, are all critical aspects of the process, but it all begins and ends with your customers. They are the ones you need to attract to the site in the first place. Before you hire a designer, hire someone to survey your core customers to ensure you get the total picture. You may find that they perceive your offerings differently than you do, are interested in new things, and/or have specific expectations that you were not going to meet had you just proceeded without their input.
Setting up a survey tool, or hiring some people to help collect the data is a relatively inexpensive process. Especially when you consider that you may discover you need to make changes to your strategic offerings before you are even ready to consider a website and SEO effort.