About a year ago (at my ex-employer), we did some hardcore SEO for Google with our site. Thankfully, we were also doing a site redesign so it gave us a chance to incorporate it all into the new design.
First of all, have good keywords in your <title> tag. That's one of the first things Google looks for.
Also, use proper document structure for your site. Your main headers should ALWAYS be <h1> tags, with subheaders being <h2> tags, etc. Be sure you have your keywords in these header tags, too, because after the title, Google looks for those and their relevance.
After that, be sure to use your keywords in the main text of your page. Google also counts the number of times your keywords appear in your page copy. However, don't "overdo" it, either, because you may get delisted for "spamming" the search engine. Unfortunately, I'm speaking from personal experience on this, so be careful.
The best way to think of any HTML page is as an "outline". Everybody did these in elementary school, so you should be familiar with it. Your main points are h1, secondary points beneath that are h2, etc. Believe it or not, Google does look for page structure, and valid, logical HTML can make the difference between a high ranking and a top ranking.
One more thing: don't use HTML tags for text sizing and effects. Use Cascading Style Sheets (CSS) to control your fonts and text appearance. It's really not that hard to use, and it makes maintaining your site that much easier in the long run. No more <font> tags all over the place-- one master stylesheet, linked to each page, takes care of that. Visit
http://www.w3.org for details.
I followed these rules for one site I redesigned, and the site ranking went from second page to top three on our main keywords. It's not as hard as it sounds, and it does pay off. The redesigned site led to more contacts and drew more business for the company, whose main hook was in advertising.
If you want any other advice, PM me and I'll do what I can. :hi: