Because it is important for the user to gain an idea of the content of the page on initial view, there should be a minimum amount of clutter preceding this - including navigation, decorative images, advertising and other material that is not central to the user's experience of the page. The user should not have to scroll significantly to find the primary content of the page.
What to Consider
Provide a short but descriptive page title.
Use clear and simple language.
Ensure that material that is central to the meaning of the page precedes material that is not.
Limit content to what the user has requested.
Ensure that content is suitable for use in a mobile context.
Page Size Usable
Divide pages into usable but limited size portions.
Mobile Accessibility: How WCAG 2.0 and Other W3C/WAI Guidelines Apply to Mobile
Mobile Accessibility Standards and Guidelines at W3C