While the facts communicated will be the same for each group, the language, voice, style and choices of illustrations may need to be very different if we hope to capture their emotions and imaginations along with their intellects. The site must be easy to 'navigate'. The client must always feel comfortable and never get 'lost' or confused as to where they are, where they've been, or how they can get to where they'd like to be. A site map is a schematic representation of your website. As a navigational aid, site maps are usually a good idea.
Consistency is essential to a successful design.
Some element behaviors are universally understood and shouldn't be changed. An underlined word of a different colour from the body text means a hypertext link that will take you to another page. A BACK arrow that takes you to the previous page of a linear sequence in some areas and returns you to the page you just came from in others is confusing and annoying. Otherwise your message will be ambiguous and confusing.