Here's one of the most dangerous phrases in web site design;  "When people come to our site, we want them to  . . . ."  It's dangerous because it doesn't address the real reason a person comes to your site in the first place . . . to get something he or she wanted - not what you wanted to give them.

Before  the first meeting with your web designer, it will be beneficial to address the question, 'When people come to our site, what are they looking for?  Actually, a better way to phrase that question is, 'When a person comes to our site, what is he or she looking for'?  Now, you have a better handle on the user experience.  Design with a single person in mind.

You may have different types of people visitiing the site.  This is where creating personas comes into play.  A persona is simply a profile of a single user.  For example, say your site sells garden supplies.  Consider the person who comes to your site.  What gender, age, level of gardening experience, might this person have?  You may find that you have two or three persona's to design toward.  That's fine.  At least you have a better idea of who your site is targeted toward.  This makes future design and usablity decision easier.  Also, please note that I made no mention of what he or she might be specifically shopping for.  Our focus is on the person, not the product. 

Let's say you develop the persona of an experienced gardener, female, and retired.  Now you have a reference point which you can use when gathering content.  It allows you to consider the relevance of each piece of information.  You may also discover that the content (which may be products) don't truly serve the persona.  Time to readjust either your persona or offerings.

My background includes two decade in radio broadcasting and audience research.  While every radio station has an audience, we would always design our format and deliver content targeted toward a single persona.  At one station, we had a full size stand-up image of a well-dressed lady in her mid-thirties placed directly across from the microphone.  Written on a sign above her were the words, 'TALK TO HER.'  Everything song we played, every contest we ran, and everything we talked about was directed at her.  The result was the station was extremely successful in that target demographic.