Most roles are now advertised using an on-line facility. Some are a national facility such as NHS Jobs, or others may use a recruitment agency or similar. Others may have their own on-line process via their website.
In most cases, you will need to complete an application form which asks for your experience, the type of work you have done in the past, personal information about you and why you would like the job.
At the time of application, you will also need to provide the name of people who can vouch for you as referees. They may be professional, employment or personal references. In most cases two references are normally requested.