Its not something that can be taught! Its something you learn about yourself really.
If your website is coded well with no bugs W3C validation passed
Has up to date and relevant information,
people link to your website as a resource
and you link to other websites to back up information on your own website,
possibly RSS feed (SE friendly)
site map (SE friendly)
easy to navigate
updated often
page titles <title> are relevant
DTD in place
<h1> <h2> tags for important headings
content flows correctly in text only mode
all images have relevant alt tags
meta tags (keywords, description) no so important these days for google atleast
See you already know this stuff! that will be £500 please... do you really think a course would be worth that kind of money? for common sense information?