As a SuperAdmin, on the Users tab >> Add User screen there is an option, "Require Email Activation". If you uncheck that box, it will allow you to define a password for the user. The user will then be able to login using that password, bypassing the email activation step:
When creating users at SuperAdmin level in bulk via the CSV upload, you can specify a password, as described here. You need to have an Email Activation column set to None and then a Password column.