A mic (behringer ecm8000 is good but also a good condenser mic) and RoomEqWizard.
Put the microphone in the listening position and follow the RoomEq istructions. It will give you a frequency response graph. But you also need an spl meter to check the right db level.
If you ask me, it really doesn't matter where you are but just be in the room, because if you test it so that you won't be in the room, it won't represent the real situation when the room is used.
You need an omni mic, those both are cardioid. I highly recommend a measurement mic, for example the Behringer ECM8000 costs only like 50 bucks so its not a big bust to your personal economy
I think that's why the people that made the program recommend that microphone - by the looks of it they have a graph showing the average response of those mic from lots and lots of samples, so they can reasonably account for the mic's affect on the frequnecy response of the room and compensate accordingly.
If you ask me, it really doesn't matter where you are but just be in the room, because if you test it so that you won't be in the room, it won't represent the real situation when the room is used.