You can edit the Loop to display anything you want. The Default them is there an en example of hat tags are available to you. But in any theme, you can edit what output is displayed.
To display images, however, you're looking for smething more customized. You cannot generally (well, you *could*, but it would require some extra work on the server's part) just place an image within the post content and strip everything away to display the image. What usually used is either a plugin or a custom query and meta data.
I can't tell you what plugin to use - since I generally just write my own code for this type of thing. But I'm sure there are several out there. Personally, I use custom fields and the get_post_meta() function to pull the images into the Loop and display the title and image (which link to the post and full content). if I want to limit how many posts are displayed (and/or in a particular category), I'll use query_posts for that.
Hope that helps!