Take a look at data-bridge/ and the "How-tos". (data_bridge_manage_relational_table.php)
Maybe they can light up your next step. :)
But in general you need to create recordsets, with or with out databas/tabel relations.
And then loop them on the page or on a area on the page (like the top 10 best-sellers).
Ex. Database with 2 tables, tbl_products and tbl_categories
if you just wanna show the products (all) on one page you make a recordset for that table then loop them on one page (by draging the field from the recordset on the bindingspanel on to the page, then put a Repeat region on that field).
Els if you wanna loop from a category u need to make a recordset for looping every product from category 1. This is good if you are to have different pages with products.
Hope i understod you right, and that it will point you in the right direction! :)
Best regards Morgan