There are two workflows available to you to start creating galleries and adding images. Please note that the second workflow requires that you have the plupload module installed. Which one you choose is a matter of personal taste, try them both and see which you prefer.

Whichever workflow you use, when done you can click on the 'View' tab to view thumbnails of your images, or you can visit the 'Manage Images' tab to modify titles, etc. Lastly, if you wish to apply a custom sort to this gallery, you may do so from the 'Sort Images' tab.