Cool. According to my researches, ideas include:
As well as enabling user font preference, increasing the default spacing between lines of text is often helpful.
Use a line spacing between paragraphs,
Italics should be avoided,
Separate, rather than embed links in text,
General consistency in layout improves predictability,
Left alined rather than justified text,
Columns should be fairly narrow, perhaps 70-80 characters wide or less,
Use bullet points and text boxes to separate ideas and simplify passages,
Pictures are still useful to break up text and should ideally illustrate the adjacent text,
Avoid using background images behind text,
Off-white backgrounds e.g. BGCOLOR="#FFFFE5" are usually better than bright white,
Ensure good contrast between the colour of the background and that of text,
For text-to-speech software:
Either avoid frames, or provide a no-frames version,
Give pictures a relevant name with the 'alt' tag,
Use full stops after headings to help the programs recognise the separation
Add an extra space plus semi-colons, commas or full stops after bullet points
Avoid words in all capital letters
I'm planning to utilise these ideas myself when we do a full re-fit on comitatus.net
Good luck Jona