Q: I need to add agency staff how do I do this and does this mean they have a username and password

A: To do this select the little button at the row of the role you wish to allocate them to.  You will be presented by staff to pick from there, ensure you select All Staff in the first instance and double check they are not on the list.  If they are not there choose New.  You will be presented with a wizard to add your staff name onto, make sure you give them a Function and a Status and ideally a Speciality (If in doubt allocate then to Non Specific), then say OK.  By doing this it will only allow you to allocate them to a function it will not give them a username or a password.  If you wish them to be able to access the system you will need to refer this to your Super User to make sure this is done.