Search Engine Optimization - Design
The types of scripts and code you use in the development of your website can play a strong role in how your website ranks in a search. If you keep good SEO Design Practice in mind when building your website, it will be that much easier for the SE's to read content on your website.
SEO Good Design Practice
JavaScript
If used wisely, it will not hurt. But if your main
content is displayed through JavaScript, this makes it more difficult
for spiders to follow and if JavaScript code is a mess and spiders can't
follow it, this will definitely hurt your ratings.
SEO WEIGHT FACTOR 0
Images in text
Having a text-only site is so boring but having many
images and no text is a SEO sin. Always provide in the <alt> tag a
meaningful description of an image but don't stuff it with keywords or
irrelevant information.
SEO WEIGHT FACTOR 0
Podcasts and videos
Podcasts and videos are becoming more and more popular
but as with all non-textual goodies, search engines can't read them, so
if you don't have the tapescript of the podcast or the video, it is as
if the podcast or movie is not there because it will not be indexed by
search engines.
SEO WEIGHT FACTOR 0
Images instead of text links
Using images instead of text links is bad, especially
when you don't fill in the <alt> tag. But even if you fill in the <alt>
tag, it is not the same as having a bold, underlined, 16-pt. link, so
use images for navigation only if this is really vital for the graphic
layout of your site.
SEO WEIGHT FACTOR -1
Frames
Frames are very, very bad for SEO. Avoid using them
unless really necessary.
SEO WEIGHT FACTOR -2
Flash
Spiders don't index the content of Flash movies, so if
you use Flash on your site, don't forget to give it an alternative
textual description.
SEO WEIGHT FACTOR -2
A Flash home page
Fortunately this epidemic disease seems to have come to
an end. Having a Flash home page (and sometimes whole sections of your
site) and no HTML version, is SEO suicide.
SEO WEIGHT FACTOR -3