Have them think aloud as they do so. Take notes and, if it's not intrusive, shoot video. These exercises should make it impossible to not get in your users' heads. By filling yourself up with all this data, you'll be grounded in these real-world experiences as you begin to design the site. Scenarios One of the best first ways for organizing your data is writing scenarios, stories which detail how a typical customer would use a site like yours.
Scenarios are powerful tools in the design process.
They force you to think the way users act - not rationally, but impulsively and emotionally. Leading a nomadic lifestyle, he enjoys using the Web to purchase from Acme, as he can do it any time and from anywhere. Wile stops into a cybercafe and calls up the Acme Products site to order new supplies. Eventually you will have to reign that in, but this isn't the time to limit your thinking. Scenarios aren't just a brief phase in the design process.