What would you call those … I’m not sure I see exactly what you describe very often. Definitely not ‘catalogs’ ‘Coupon book (or booklet)’ only if you actually need the booklet to get the discount. Otherwise ‘Flyer showing specials’ ‘Flyer showing discounts’ ‘Flyer with manufacturers rebates’ ‘Flyer with on-sale items’ ‘Sales flyer’ depending on the details.

The little booklets or printed materials that contain ads and information about products from different companies are typically called "catalogs" or "product catalogs." These catalogs are often distributed by stores or companies to showcase their products and promotions to customers. Regarding your second question, it is correct to refer to the content in these booklets or flyers as "ads" when they are promoting products or services. Ads can take various forms, including those in print media such as catalogs or flyers. So, you can use the term "ads" to describe the promotional content in these booklets.

It depends. It could be a product catalogue or a coupon book (coupons offer discounts on the products).