Make sure that there is a good contrast between copy and background - use the 'Design' section to change the default text colours and background colours so that they are in contrast.
Don't put together colours such as red and green or green and blue because these colours are difficult for people with colour blindness to distinguish between - most objects on the page can have their colour changed using the 'style' panel in the SiteMaker Editor.
Don't use colour to get people round your site, for example don't tell people to use the red button to move to the next page, some people won't be able to see the colour or even the button.
Clearly explain the content of any audio, video, flash files supporting copy. This helps visitors who have screen readers, it will read out loud what you have described…but of course it can't read a picture! - you can use the 'alt tag' button on the 'style' in the SiteMaker Editor to add alt text, or for items where this is unavailable, you can add an additional text box that describes the interactive object.
All images have appropriate alt tags or blank alt tags - Use the 'alt tag' button on the 'style' panel in the SiteMaker Editor to add alternative text for images and widgets.
If you are using difficult, uncommon or foreign words, it's important to define them perhaps in brackets (after the words) or maybe through a glossary.
Don't use a style that looks like newspaper columns - this kind of layout is very difficult for dyslexics to read…even if it does look nice!