I got into
SEO only a short time ago. Before that I was working for a web design company. It became quite clear to me after looking at site after site that if web designers were taught how to build w3c compliant sites and considered the search engines while building a site there would be a lot less
SEO peddlers about. I started studying html only a few years ago and the only nod to the search engines was to include meta tag keywords in a pages html. This may not be the case at every educational establishment but it sure was at mine.
When I was studying it was stressed that w3c validation was an important thing to strive for and it is. When building a site it's easy to dismiss a few errors in favor of getting a site cross browser compatible but you should not feel that your website is finished until it validates. Although it's still debatable whether or not having a validated site helps with
SEO, it's a good habit to get into. It's generally easier to optimize a site from scratch so here's a few tips to think about when designing your next masterpiece.
Name the pages based on the keyword that you would like that page to rank for. Choose one main keyword per page to avoid diluting your keyword. Include a keyword in the name of your image folder and any other folders that are only one sub directory deep. This means your keyword will pop up more in your pages code. It's always tempting to use Javascript image rollovers for the navigation but the javascript code seems to confuse googles crawler spiders so if you can, use css instead. When writing the code for the navigation be sure to include full urls's, i.e. the full path to every page, and include your keywords in the anchor text of your links. This will help your internal linking structure.
As for content, lots of text, images and video. Including your video as a flash .flv file and then submit a video sitemap to google. Content is boss so jump to it.
Source -
http://www.buzzle.com/articles/web-design-for-seo.html