For successful results from your website, I would have to say that the ease of navigation for your visitors when they first visit your website is the most important upfront web design factor to test.

Why? Because if your customers never make it beyond the first page of your site(your homepage), how will they ever get to the sales page -- which is the desired finish line, right?

Think back to a really great site you've visited recently and how easily you maneuvered around that website. Probably, the homepage had links down the right-hand or left-hand sidebar, an introduction to tell you a little about the site and/or the product or service offered, and no doubt the site had a purpose.

This key factor is exactly what's missing in many sites, and because it's missing, "visitors" seldom turn into paying "customers."

Below are two distinct methods you can use to test the navigation of your website:

1. Use your web host's website statistics. Your statistics will relay to you how many visitors are coming to your website, which pages they visit the most, the most popular entrance pages and exit pages, and how many pages were visited in your site versus how many visitors. The statistics you will want to concentrate on are the exit pages as well as the number of pages/number of visitors ratio.

By checking your exit pages, you can find out if a large number of visitors are exiting your website from the homepage. If the great majority are exiting from your homepage, you may want to make some changes on your homepage and test different layouts and content.

Your total number of pages visited versus the total number of visitors helps you to determine how many pages your visitors clicked to while visiting your site. For example, if your total number of pages is 1,400 and your total number of visitors is 700 for the same period of time - such as within one week or one day, then your total number of pages per visitor would be 2. The way I arrived at the figure 2 was by simply dividing your number of pages by the number of visitors. This tells you that many of your visitors are at least clicking beyond the first page entered. This could be good or bad, depending on what type of website you have, your product or service, and sales presentation.

2. The second method is to let your family members or friends visit your website for the first time with "you" watching from behind. You will observe their actions and reactions to your website. They may not tell you that anything's wrong, but you can test your navigation simply by watching their movement. The most important thing to watch for is a stopping point. If your friend/relative comes to a stopping point where he/she does not move forward(reading or clicking), this may be a place on your website for you to test a different method. The only exception, of course, would be if he/she "stops" to order your product. :-) In that case, don't change a thing! And, by the way, don't tell your friend that you're observing for anything in particular.

Remember, don't just design a website, design an effective website.
Now that you know how to test your website's navigation, go here to read a continuation article on the subject... "How to Make Your Homepage Flow" to learn some techniques that will help turn your visitors into paying customers....
http://www.webmastercourse.com/articles/make-your-homepage-flow/