It's important to know your audience. Write and design with your visitors in mind. Try not to write for yourself.
Do write about the subject:
Write about the subject. Saying: This page is about breeding goldfish talks about the page. Instead, start right away with the subject. Breeding goldfish is a popular hobby....
Do choose the right fonts and sizes:
Making your section titles the right size will greatly effect the experience your visitors have when viewing your websites. Generally speaking, you should use the paragraph size for content and reserve header formats for the the titles of the pages and sub-headings.
Do check your links:
Check your links frequently. Don't just check them to avoid 404 errors. You might find that an external link still works but that the content behind it has changed.
Don't use jargon:
Avoid jargon. That goes for Internet jargon but also for jargon for any other subject.
Only if your site is focused on a selective group of specialists jargon might make sense.
Don't show any page under construction:
Don't publish a page that's under construction. If the page isn't finished, it's not ready to be published.
Do use navigational aids at the top and the bottom:
Supply navigational aids at the top and the bottom of your page. If you do, people probably won't need to scroll to navigate.
Do keep menu items related:
Menu items should be related, don't mix them randomly. Try to share comparable items in one menu. You can use a larger menu for more itemgroups if you separate these groups in a clear way.
Don't mix horizontal aligning:
If you want to center text do it consistently. Exceptions are centering text of headers or centered text placed in a border.
Don't use all capitals:
DO NOT USE ALL CAPITALS.
It takes more time to read text that consists of only capitals. Besides, using all capitals is the online equivalent of shouting.