When you design a site, it's important to keep the navigation simple and easy to understand. Certain web design elements have become part of the collective consciousness; your users expect your site to act and behave in a certain, standard way. When your web design deviates from the norm, you force your users to think harder about how to move through your site. And the more difficult it is to navigate your site, the less likely it is that people will keep browsing your site; they'll just get frustrated at some point and leave.

Here are some elements and design concepts that are commonly expected:

• Clickable logo in the top left corner - Quick, how many sites do you go to that don't have the site's logo in the top left corner? It's probably a very short list. When people get lost in a site, they know that they can click on the logo in the upper-left corner to take them back to the Home page. Ah, safe at home....
• One main navigation - Have one, main navigation for your site, preferably located across the top or down the left side. And make it obvious that it's the main navigation. People won't spend a lot of time hunting around on your site if they can't figure out how it's organized.
• Don't change the main navigation! - I can't emphasize this enough... never, never, NEVER change the items in your main navigation as the user browses through your site! The fastest way to get people totally confused when moving through your site is to drop elements in your main navigation on different pages.
• Sub-navigation bars are extremely helpful - your website is a lot bigger than just the categories in your main navigation. It's ok to have the main navigation expand to show sub-navigation items, or have the sub-navigation in a separate area altogether. Just make it obvious to the user that this is a sub-navigation menu, and not the main navigation.
• Keep your site map logical and consistent - The more categorized you can keep your site, the easier it becomes for the user to intuitively understand it and find what they are looking for.

Is it ever ok to deviate from these standard elements? Absolutely... but only so long as it's obvious to the user what you've done; therefore, make sure you put a lot of forethought into it. For example, do you want to put the logo in the bottom right corner, instead? Then you might consider making the height of all your pages a fixed size so that the logo never disappears off the bottom of the screen. And you might want to make the logo extra-large, just to call attention to it.

The point is, A good interface design just works. People who arrive at your site should be able to intuitively understand how everything operates. Don't make them work for it.