How Do I Upload Files In WordPress?

Q: I want to be able to upload images (for ads, banners, etc.) without having to FTP in. I’ve been doing it by adding them to a dummy post and then copying the link and adding where I need it-is there a better solution? A: There’s a built in solution for WordPress to do just this. In the sidebar of the WordPress Admin Area, click on “Media > Add New” (located at http://yoursite.com/wp-admin/media-new.php). From there you’ll see the same file uploading interface that you do when you create a post or page. If you need assistance, please contact WordSprung.

Source: WordSprung » WordPress Q&A