Integrating payment to your online business depends on what platform your online business is hosted on. Like people who do drop-shipping and use Shopify, there are payment providers that support crypto payment (I don’t know what their fee rate is though). But if you want to handle it yourself, it’s as simple as putting the payment wallet address up there. All crypto transactions can be sent to the wrong address so it is the duty of the sender to be watchful and cautious when making the payments. For a user to even use cryptocurrency to pay you, it means they already know how it works. By the way, have you decided what cryptocurrency you want to accept for your business yet? This matters too.
These days, it is quite easy to set-up crypto payment method as you just need your own wallet and net connection.
Also, one should think of other alts other than btc as the fees are quite outrageous.
Should think of LTC, DOGE or XRP or other popular alts with low transaction fees and can found in most trading platforms.
Though the OP can start from one alt, and just add when he feels his customer is getting acquainted with other alts.