Follow this link to register at the VRM pool: https://vrm.poolsloth.com/index.php?page=register
After registering, you will have to create workers: https://vrm.poolsloth.com/index.php?page=account&action=workers
The worker credentials will be used to identify and authenticate your mining software. Please note that the worker password is transmitted in the clear and can only be used to perform work on your behalf. It is not critical to make this a complicated password, a single character is fine.