Create a Gallery Assist (GA) gallery. Go to Create content and select the Gallery Assist node type called "Gallery" or other node type with Gallery Assist Assignment.
Give a name to your article and save. Gallery Assist extend the article with a new field or object (the gallery container) so the module need the NID as argument for the creation of the gallery folder structure. Once the article is saved click to edit it.
Two new fieldsets are added to the node edit form:

1. Fieldset "Gallery Assist (GA) settings"
2. The Fieldset "Gallery Assist (GA): Add and edit items" wich will be just explained.

Select the files you want to add to this gallery and click update to upload.
If the pictures have a copyright use the field Temp copyright to avoid unnecessary work. In the background, the folder structure will be created if not exist, images are stored, copied and new formatted as necessary.
If this process failed, please read the list of posible causes for this issue and pubilc the issue through the Drupal Issues Reporting System (at your accout profile in drupal.org). If images were successfully uploaded, the form will be rebuild with the new changes. Now you can:

1. Add new images to the gallery.
2. Change the captions and the copyright information as wanted.
3. Change the order of the pictures thanks to the functionality of tabledrag.
4. Add a description to each image.

You can to add a description to the gallery, task that belong only the Drupal node process. Are you satisfied with the results, save the node and view it.