Create a “best sellers” or “featured items” list on your website (preferably on your home page).
Consumers want to know what other consumers like. It's how they know what businesses to trust.
I do think there will be companies out there who "say" things are Best Sellers when they really are not, but I know you're the wonderful, honest type.
Your homepage is the best place (in my opinion) to host a section of your best sellers because it will be the first page most people interact with. You could also host this section at the top of your "Shop" page that lists ALL of your products. It's up to you.
Alternatively, you can have a list of "Featured Items", which would be products that you want to push, rather than what the Best Sellers are. These could be products/offers that you are looking to promote during this challenge or ones that have the highest profit margin for you.