Anayeb,
The visa will be an antry visa that will cover you for the short visit. It shouldn't take long to issue and you may not actually receive it. You may receive a letter (or e-mail) from QP that you can show to the airline advising that one is waiting for you upon arrival in Qatar. You will probably receive a PTA (Passenger Ticket Advice or PTA number) that you can confirm with the airline.
You will probably be shown around Doha (after the interviews) with particular attention to the temporary accommodation provided (probably for the initial 3 month period) and other facilities.
Unless things have changed dramatically the above is probably correct.