Few people realize that with today's modern browsers, relative sizing can in fact be added to images as well as text elements on your web page.
Therefore using absolute or relative sizes for your layout, keep in mind screen resolutions.
More about this:
http://www.wats.ca/resources/relativesizing/20
Using tables if complicated, Web authors are encouraged to use the summary attribute of the TABLE element. This, like the longdesc attribute for images, is not represented visually. It is rendered from the HTML code by assistive technology like screen readers and talking browsers.
The summary attribute should contain, as its name suggests, a summary of what the table presents.
With a summary, a blind person using a screen reader (which supports the summary attribute) will have an overview of the table before he starts to read it.
More about accessible tables:
http://www.webaim.org/tutorials/tables
http://diveintoaccessibility.org/day...ent_first.html
http://www.mcu.org.uk/articles/tables.html
http://diveintoaccessibility.org/day...e_headers.html
If the above do not answer your questions, have a look here:
http://joeclark.org/book/sashay/serialization/
If you still have any further questions, please feel free to post.