There's a lot of debate concerning the advisability of using plastic against a below-grade masonry wall. I agree that it
seems a good way to get liquid water that comes through the wall down to your drainage system. On the other hand, adding the plastic assures that there will be virtually no drying to the inside of the room, that any water vapor that comes through the wall will remain stuck behind that plastic. That can become a mold colony--I don't know what the mold is eating, but it can happen.
Insulation is another big issue--fiberglass is not the best answer usually, unless an inch or so of rigid foam insulation is placed against the masonry first. Given typical inside and outside temperatures, the foam assures that air inside the room does not encounter a "condensing surface"--a surface below the dew point of the inside air. If the foam isn't there, water vapor from inside the room easily flows through the fiberglass insulation, reaches the cold concrete wall and/or plastic, condenses, and forms a mold colony inside the fiberglass. Adding another vapor barrier on the inside of the wall is doomed to failure--two vapor barriers is always a no-no. The second link below has a few pictures of the mold that results with two vapor barriers. Bad.
With the foam against the wall and proper detailing, you've got a barrier that stops liquid water that leaks in from the outside from reaching your wood and fiberglass (if you use fiberglass). If you have an inside perimeter drain, the water will go into it if you've left a way for the water to get tot he pipe. The foam "breathes" a limited amount--mass air (with H20 vapor) can't pass through it, but it does allow water vapor to permeate. So, a wet wall can dry. Expanded polystyrene foam ("beadboard") has a perm rating of above 1.0 per inch of thickness, which will allow limited drying to the inside. That's what we want.
Here's a good site explaining everything briefly.
More, with more detailed explanations.
When I do my basement I'm going with 2" of rigid foam and furring strips to hold it to the wall and to which I will affix the drywall. I'm using the type of drywall without any paper on it to help avoid mold. I'll keep the drywall at least 1" above the floor (covered by a plastic baseboard) in case the water finds it's way in (or a burst pipe in the basement pumps it in). I spent a lot of time last year digging an external drain below the level of the footers and another to take care of ground water higher up, so I think I've done all I can on the outside of the house.