SEO is intimidating to a lot of people, but it's really just a matter of making the time to do the reading/investigation/experimentation/implementation. Here's a useful "SEO starter" article I think you'll find useful if you're looking to get better search rank for your own site, or want to get started learning so you can help your clients.
And be sure to check out the other SEO blogs and resources mentioned in the article as well - my personal favorite on the list is the Google Webmaster Blog
In the past, I used GNC Web Creations to learn about SEO and marketing strategies. There are also courses on html, css, etc.
You sign up and she emails courses to you to do at your own pace. They are actually very informative. The web classes are pretty in depth with submissions and "tests" to check your understanding.
Online resources to learn SEO
Shellye L. Lyons, Business/Marketing Manager ~~ 
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