After Permalinks, the Reading Settings is likely the most widely used settings page in WordPress. This is where you can set any one of your pages to act as your home page. You can also move your blog posts off of the front page of your site.
This screencast also walks you through the other settings that control a number of display options and have an impact over how your site appears to visitor. Use these settings to limit the number of posts that appear on a page and control your RSS feed.