The whole process is pretty easy and company employees will just need to sign in the Google Play client with their company email address to browse the Private Channel and download apps.
Google Apps customers will however still need to pay $25 to make an account with Google Play developer console and publish their apps. There are some restrictions as well – first, each organisation can only have one Private Channel, secondly an app cannot be published to both the public Google Play store and a Private Channel.
The whole process of publishing internal apps on a private Google Play channel has been described here.
