The rules for the Coronavirus Job Retention Scheme can be found at:
In particular please note:
The scheme is open to all UK employers that had created and started a PAYE payroll scheme on 28 February 2020
At the time of writing (30/03/20) HMRC advise that the online service to be used to claim is not available yet. It is expected to be available by the end of April 2020.
Employers will need to make any claim, within the qualifying rules, and any amounts received will be paid to the employers (the company in the case of businesses trading as a Limited Company) and it is our understanding that the amounts will be treated as taxable income offset by the payment of the salary.