What makes website design effective? What makes some websites earn money and others don't?
Internet is a massive place. It is full of information, interests, resources...or distractions.
When a user visits your page, you have approximately five seconds to convince them why they should read your website.
Fast website means faster load times. Avoid displaying heavy elements which upfront: Flash navigation, large detailed images/photos, text that cannot be read until the background image loads, etc. Emphasis on very focused content instead of long story, and make the supporting materials (detailed images, maps, detailed stories, etc) available only when the users want to view them; i.e., present them as hyperlinks. If long content cannot be avoided, try programming the page to load up gradually; e.g., use text that is readable on white background while waiting for the background image to load, etc.
Clear website allows easy-to-find and easy-to-use navigation. The navigation tools (linkings) must be easy to find on-screen and allow the users to quickly find the information they need.
If the users cannot find and start reading contents relevant to their interest in 30 seconds, it is more or less a game over.