Originally Posted by StarkReality

If you are using a newer version of wordpress, there is no need to write anything to a .htaccess file (which can be made in a text editor, named to .htaccess and uploaded) because wordpress handles permalinks internally.

Go to -> Options -> Permalinks in your admin navigation, select "Custom, specify below" and insert something like /%post_id%-%postname%.html

The example above would create permalinks like /124-the-name-of-my-blog-post.html

Advantages:
1. No ugly deep directory structure, which would prolong the process of g**gle crawling your blog
2. If you create two posts with the same title, which can happen easily, for example if you import large sponsor feeds, it's still two seperate permalinks because of the unique post id in front.
3. Keywords repeated in the .html file name
4. Changes in category name or deletion of categories don't affect the posts or make them invalid.