Hi. The gallery page is easy to setup. Just follow its install instructions and you'll be right.
As for the customization of the look (including adding the banners and stuff), you'll just need to modify the html_wrap files (not sure of the actual name of the folder but it's something like that). Again, the html_wrap files are the templates used by the gallery system so modifying those changes the look of the gallery. Be sure to read the comments on those pages and follow the instructions.