It is quite possible that they will ask you your salary expectations. So do a bit of research as to what the going rate, or range, is. IMHO, when asked, name a figure at the higher end of the range if you think you're worth it. It's rare that the employer will offer a higher figure than what you've offered. On the other hand, don't overdo it. If you ask for something too high, then the employer will most likely think that there's no point in making a much lower counter offer, and simply make no job offer at all.
It's certainly not easy :-(
But if they don't bring it up, I wouldn't ask about salary at the first interview either.
Edit: Just saw from previous threads that it may be a civil service type job. In that case there will be defined pay structures and you won't have to worry about the "salary expectations" question.