When taking over a site that has not been optimized for SEO, I like to go over these steps to ensure that all bases are covered in making the website SEO compliant. There are obviously a lot more ways to ensure SEO compliance, but these are the main few steps when taking over a website that has had no optimization.

In order of importance:

1. Title Tags: This is one of the most important SEO tactics that you can use that will immediately help you go after keywords during a search. One thing to keep in mind when creating the title tag, is to ensure that every word placed within the title tag is  written somewhere on the site. Otherwise, google, yahoo, msn may frown upon this. 
<title>Reno Website Design | Sparks Web Development | Professional ColdFusion Web Design | WeCodeThings</title>

2. Page Names: Ensure Page Names are SEO friendly. i.e. : wecodethings.com/seo_website_friendly_names.cfm

3. Ensure robot.txt file is set to:

User-Agent: *
Allow: /

4. Create all Meta Tags

• Discription: <meta name="description" content="This needs to be a lengthy description" /> 
• Robot: <meta name="robots" content="all" />
• Author: <meta name="Author" content="WeCodeThings, Website Design Reno, www.wecodethings.com " />
• Distribution: <meta name="distribution" content="global" />
• Keywords: <meta name="keywords" content="all, key, words, are, separated, by, a, comma, no, more, than, 20" />

5. W3C Compliant - W3C Validator

6. Footer: Place main keywords that you are SEO'ing for in the footer for each page.

7. XML sitemap: Create a XML site map that you upload to Google.
http://www.xml-sitemaps.com/

8. Sign website up with Google Local Business: Google Local Business
Be sure to list for as many categories as you can as well as uploading images.

9. Broken Links: Ensure that there are no broken links within the site.

10. Alt Tags: This is mainly for google, yahoo, msn images, but it does help. Ensure alt, height, and width attributes are included within each image on website.

11. Current Dates: Check to see if website has dates in static text, like: Updated 2006. Be sure to update these to the current year. Search engines prefer up to date websites.