there's a good article on this today on Webpronews site.
Jason miller listed this top ten tips...
1. Title Tags - The words in the title tag appear in the link that pops up in the search result. Each page should have a title tag as Google ranks each page individually, not the site in its entirety.
2. Content - content should be quality. Keyword use and keyword variation should be natural and not overstuffed.
3. Links - backlinks, links to your site from outside sources. Links are your letters of recommendation.
4. Quantity of links. "you can't buy Google's love that way". He was referring to link swaps. A large burst of low-quality, non-authoritative, or bad-neighborhood links, though, can do a lot more harm than good; so keep things natural.
5. URLs - keywords in the URL are a good idea. Keep it short and avoid super long URLs that are encoded.
6. Spider Food - Search spiders eat HTML, not Flash. They eat text, not pictures. Make the spiders happy with HTML and lots of text to eat.
7. Site Architecture - Use sitemaps to help spiders crawl.
8. Fresh Content that are frequently updated.
9. Start a blog - write a quality blog. It adds keywords and make you an expert.
10. Humans - make a site for humans too!
http://fly2.ws/ukAeNvx