what do a post doctoral do?


Hi, I'd like to apply for a postdoctoral position, which I'm very interested in. But the subject is not the same as my PhD topic. So, do I need to read a lot of backgroud papers before I apply for it? Or will people have time to read papers after they start work?

And it says 'to function as a senior member of the research team', does it mean that the people in the position need to respond to other members and be responsible for the whole project, well, at least in some degree? I mean, He/She does not ask for the supervisor's advice for everything, does he/she?

So the post doctoral is supposed to be more independent, desige/conduct the experiemnts, analyse the data, report the result and write up all on their own? And then, what does the supervisor do?