There’s a link to the theme description and the options in the footer of the theme. http://theme.wordpress.com/themes/forever/
See > A Dramatic Personalized Home Page
You can have a featured posts with featured images in a slider on your home page. You need sticky posts with Featured Images. Every sticky post you have (up to 10) that has a Featured Image (at least 888 pixels wide) attached will show up there.
Note that Optimal size for featured images is: width 888px, height maximum 355px.