CV3's wholesale functionality allows retailers (who have registered and been approved by you for wholesale status) to log in and then they are presented with an order form - they are not able to just navigate around the site to make their purchases like a normal user would.
To see an example, go to http://cv3demo.commercev3.com/wholesale_login and log in using email@example.com with a password of testing.
Click the "Create an order" link at the top once you are logged in. This is an example of the wholesale order form. Only products that have the wholesale fields set up will show on the form.
You can also play around with it on your own site by registering and approving yourself. You can get to that area on your website by using /wholesale_login in the URL. It gives you the option to register via a link.
In your store admin, you can see the Wholesale area - there are separate shipping tables for these users.
From a data perspective, you would need to enter or upload the wholesale prices for any items that would be available to your retailers.
Refer to product import documentation: http://docs.commercev3.com/index.php/Product_Import - fields in question are below, which would be included in your import file along with SKU. Note that attributes do NOT work with the wholesale form.
IsWholesale | "TRUE","FALSE"