Conventions are the things that the people are used to seeing or expect when they browse a website.
- Never use underlined text. It is easy for people to confuse underlined text for links and try to click them.
- You don't need to indent the beginning of paragraphs.
- Try to make links descriptive of where you are taking the user. Try not to use "click here" instead use words that describe the content you are taking them to. That will make it much easier for the user to scan text and find the link you are pointing them to.
- The most common unit of measurement on the web is the pixel. This is important for sizing images for the web. See Image & Photo Tips for more information on how to use this.
- Keep in mind people can only read 80% as fast on a screen as opposed to a printed page.