Good Web Site Design Practices

Your website represents your business online. It's really important use design practices that will ensure that your site appeals to the maximum number of visitors.
The most important aspect of good web design is the navigation. Poor navigation can quickly put off a browsing visitor, so make sure that the navigation menu is well focused, and concise.
Try to keep the number of images on your site to a minimum. Optimise all images to reduce load times. Images always slow down the loading time of web sites, so only display images that are necessary. Never use large images as thumbnails - always resize the image, and link to the full size image if necessary (I've seen site with 800 X 600 px photos used as 200px wide images - and the site owner wondered why it took so long to load!)

Keep all of your text blocks down to a manageable length. Most people can't be bothered to trawl through huge, dense chunks of text, and will simple skip over them. It just adds to the frustration factor, and may cause users to leave quicker.

Check your website for functionality on all browsers - Chrome, Firefox, and IE7 to IE9 (there is still a debate as to whether IE6 should be supported, but I think it's getting a bit tired now).
Try to use CSS for all styling and positioning - it can make your site perform better, and make it much easier to maintain.