With Guest Post Publisher you can let your users post articles on your site from the front-end, using the built-in WordPress editor and media library, which are familiar to most and makes this plugin as lightweight as possible. The featured image on your site will be clickable when in edit mode. The images the user can view in the media library are limited to images the current user had uploaded.
Because the plugin makes the featured image clickable, it will have the look and feel of your “normal” pages, and the featured image will look like it will when published.
Users can log in either with the WordPress user login system, or you can require them to create a one time login with email validation.
How to get started
Simple create a page, and add the shortcode gpp_editor. With the pro plugin (to be released soon) you can also add custom fields, and let your users post to a custom post type, or any post type you would like. This way you could let your users create events, posts, or whatever you might think of.