1. The first thing that you have to know - content is your number one and it's your primary priority. Therefore, make sure that you publish good, clear and unique content that is based and focused on your target keywords.
2. Quality backlinks is your number two. Buliding of a network of backlinks is a very important thing in terms of Search Engine Optimization. Make sure backlinks contain your keywords or key phrases between the tags.
3. Remember that one single link from a good site can beat 10 links from other 10 web sites with poorer quality.
4. Fresh and unique content published on a regular basis improves your rankings. Try to keep your site up-to-date as much as you can, try to publish new content or update the existing one.
5. Pay your special attention to the <title> tag. Put your keyword in the beginning of this tag.
6. Setup your .htaccess file so that it handles HTTP errors such as 404 and 403. It's a very good practice to display a nice site map instead of ugly default "Error 404" page.
7. Describe your images on your pages using the "alt" attribute.
8. Ask your designer to design your web site considering SEO.
9. Don't forget about usability. Remember that you create a web site not for search engines, but for real people.
10. Work on SEO optimization on daily basis. Use tracking tools to monitor any changes in your web site traffic and correct your SEO strategy accordingly.
11. Do not use a submission software or online service! Submit your web site to the search engines yourself or put the link to your site on any web page that is already indexed by search engines.
12. Despite the different opinions use meta-tags such as keywords and description. Make those tags unique for every single page.