This plugin creates an image slideshow in your theme. You can upload/delete images via the admin panel, and display the images in your theme.
The plugin uses built in WordPress functions to handle image uploading. Therefore, you need to have correct permissions set for your uploads directory.
Also, a file that is not an image, or an image that does not meet the minimum height/width requirements, will not upload. Images larger than the dimensions set in the Settings of this plugin will be scaled down to fit, but images smaller than the dimensions set in the Settings will NOT be scaled up. The upload will fail and you will be asked to try again with another image.
Finally, you need to verify that your upload directory is properly set. Some hosts screw this up, so you'll need to check. Go to "Settings" -> "Miscellaneous" and find the input box labeled "Store uploads in this folder". Unless you are absolutely sure this needs to be something else, this value should be exactly this (without the quotes) "wp-content/uploads". If it says "/wp-content/uploads" then the plugin will not function correctly. No matter what, the value of this field should never start with a slash "/". It expects a path relative to the root of the WordPress installation.
There might be some jQuery conflict in your site. Please try moving the
<?php wp_head(); ?> to the right before of the
</head> tag in your header.php of your current theme folder.
Chronologically, from the time of upload. For instance, the first image you upload will be the first image in the slideshow. The last image will be the last, etc.