Designing a web site needs careful thinking and planning.
The most important thing is to KNOW YOUR AUDIENCE.
Users are Scanners
A typical visitor will NOT read the entire content of your Web page!
No matter how much useful information you put into a Web page, a visitor will only spend a few seconds scanning it before he/she decide whether to leave or to stay.
Be sure to make your point in the very first sentence of the page! After that, try to keep the user occupied with short paragraphs, and new headers down the page.