@anapper: Catch Everest Free theme only have Featured Post Slider. This means you can only add in your posts as Featured Slider. The image, title, and content are taken from the post.
1. First create the Post and don’t forget to add in the Featured Image in the post as this image is used in the slider. To add featured image see this http://en.support.wordpress.com/featured-images/#setting-a-featured-image
2. Then get the ID of the post. When you edit your post or write a post, you will see the id in your browser address bar. Also you will see the Post ID in All Posts section. But if you cannot find it then you can use this plugin to view it http://wordpress.org/extend/plugins/catch-ids/
3. Then go to “Appearance => Theme Options => Featured Post Slider”. Add in the post id.