Well... it depends on the tutor and the student!
I cover all three, for example, but I know some others who specialise in texts or tasks they feel confident in and don't do others. Of course, just because a tutor does all three responses, it doesn't mean they're equally strong in all - but I think it is still preferable to keep the same tutor for the whole year, as you adapt to each other's styles and most students have stylistic/technique strengths and weaknesses that persist across tasks: it helps when your tutor is already familiar with you.
What you cover depends on the tutor and the student, but I do more than that and I know others do, as well. I go over structure and style of each piece; ways to collate and organise notes; developing the content itself; analysing and responding to prompts or source material; planning responses... and then, of course, giving feedback on responses. But you have to be flexible depending on the student, the time of year, how quickly the teacher jumps into the SAC, how well the area is done in class, etc.
Really, I think you need to consider what *you* want to get out of it, then look around ATARNotes and ask your friends to find someone who might suit. Meet with them; show them your work; ask them some questions; outline what you thought might be good; and in the end just go with someone you have a good feeling about!