Here’s a quick list of what you’re supposed to know for doing some basic seo. It’s the minimal technical background I think it’s necessary to start some Search Engine Optimization. You don’t need a deep knowledge of this, but you definitly need some basic comprehension of how this stuff works.
Keep in mind we’re talking about technical skills, we’ll talk about non-technical ones in a future post.

HTML

When writing your content you can use a WYSIWYG editor, but before publishing it it’s better to review the html code to perform some optimizations… so you should know how html works.
We’ll talk deeper about html optimizations in the future, but basically you need to help the spiders to better understand your page structure and topic by using correctly

• page title
• headings
• paragraphs structure
• img alt tags
• titles and texts for links
• …

If you need some basics of html, you can start from this html tutorial

CSS

Ok, spiders don’t care about the way your website looks, but users do. And you should focus more on your users than on the spiders.

You’d better start to learn some css basics if you don’t want to depend entirely on the free stuff you can find on the net: free themes / styles / templates are cool, but you’ll always need to tweak them to fit your needs.

You may find intresting this css tutorial

Usability

Your site should be

• easy to understand
• easy to explore
• with an intuitive structure
• accessible

If you think you may need it, have a look at www.usability.gov :)

Copywriting

Copywriting is the process of writing the words that promote a person, business, opinion, or idea. […] The main purpose of writing this marketing copy, or promotional text, is to persuade the listener or reader to act – to buy a product or subscribe to a certain viewpoint, for instance.

And even if you’re blogging about your cat, you’re trying to persuade the listener to act: the first line should convince the visitor to read the second line, the second line should convince the reader to read the third line… etc.

Visitors are are spending their time on your site: you’ve to keep them reading about your cat instead of going out with their girlfirends! :)

Copyblogger is a good site about copywrting stuff for bloggers.