To get started with Amazon coupons, go to Amazon.com, then click on the link at the top for "Today's Deals.". In the menu of subitems, click on "Coupons.". You can also use this direct link.
To find promo codes: Type “amazon coupon codes” or “amazon promo codes” into your search engine of choice (one will most likely find results for the other). Then click on a link like the ones highlighted in the screenshot below.
There are a couple of ways you can get discounts on Amazon. The simplest is to click on "Today's Deals" to bring up Amazon's Gold Box discounts, which can include coupons, lightning deals, deals of the day, and Prime early access. You can also search Amazon Warehouse for discounts on returned or refurbished items as well.
Coupons You Digitally “Clip”. Amazon has a ton (like 1,000’s) of digital coupons that you clip before you buy, then the coupon savings automatically gets added when you make the purchase. These coupon offers are all found on the somewhat hard-to-find Coupons Section of the Amazon website.