well, "creating a gallery" is a broad topic.
your first step, actually the first step of any web development project is start by planning what you want to accomplish in the end, get out the old pencil and paper and story board the idea.
do you want to have only one gallery?
or multiple galleries?
do you want to add to the gallery dynamically?
once you have a more concrete idea of the end goal, you can start developing.
starrt with creating any database tables you'l need.
If you want to have multiple galleries, you will need a galleries table:
galleryID - Primary Key
and a gallery images table:
galleryimagesID - primary Key
galleryimagesGalleryID - relates to galleries.galleryID
you will need to run the data assist wizard to create a page to manage the galleries
then another set of pages to manage the images for the galleries
you'll also need to use security assist to create a login page and to restrict access to the gallery admin pages.
you will need to run the data assist wizard again to create the public search results and details pages for the galleries and to display the gallery images.