If you are a web developer, you wont need to read the rest of this page, as I'm still learning towards making a good SEO for my own blog. But if you're still getting started to make your blog or website, this is some information that you might want to consider before posting a post in your blog.
Sometimes, we make a blog just for logging our thoughts, and keeping our experiences from being forgotten. However, for an informational blog like mine, visitors do counts. What's the point of writing an informational post if no one reads it?
The way which most visitor come is through the search engine like Google, Yahoo!, Bing, etc. Those search engine will send their crawler (or spider, just a different name) to you blog, and index every page available. The best way to make our website more friendly to these crawler is through a good url. An url like http://yourdomain.com/archive/2011/03 is better than http://yourdomain.com/index.php?archive=2011-03. However, I still haven't figured out any way to implement it to a single file blog (my blog consist of only index.php). Making many directories is tiresome, but it worth the effort.
Search engines hate image and flash, they love text. That's why every image needs to have an alt component to give some clue to the search engines of what the image is about. A title tag and meta tag in your document head will also be a good friend for search engines. Make sure these tags have no duplicates by making them dynamically change in every page with php.
As for flash, never use it if it's unnecessary. The worst website that search engines won't be liking is a website filled with flash animation but have no actual text. If you want to make a flash website, make sure that the texts in your flash animation always synchronized with the actual text. If you don't know how to do that, simply don't use Flash in your website.
The most important thing to get traffic to your website is through link sharing, and lots of it. You can do that by actively commenting in another blog or website (no spam, of course) and by actively contributing in forums. You can also do this by sharing your posts in social networks such as twitter and facebook. Do this regularly, 7 times a week, and you will sure get traffic for your website.
That's all I know, I'm not an SEO master anyway. Hope that helps.