I sometimes have to shoot in an enclosed space, a living room that is somewhat similar to the picture below. There generally is a large French window on one side that is streaming in sunlight of late afternoon. The remaining three sides of the room do not have any windows and if there are, they are tiny and with frosted glass so they do not count as much towards lighting. The left part of the room which is sunlit has no other lights. The right part of the room is lit with CFLs. And I am shooting because of an event that is happening and that means there are quite a number of people and kids doing their things. I generally shoot standing somewhere in the middle of the room, close to the sofa in the middle.
One of the problems I have had is the extreme difference in subject lighting. This has meant I have had to change shutter speeds, stops and even ISO frequently based on which side of the room I am shooting. All this means, I miss some shots that I would have liked to take. Hardware wise, because of low light conditions, I use a 35mm, 1.8 prime instead of the kit of 18-55 on my D3000 and that's what I have got.
So my question is what are your tips to shooting in such a space? Perhaps you have suggestions to where I should stand, any lighting I might use in the rooms, seating arrangements of guests, any useful shooting modes apart from Manual, etc. Ideally, I would want not to go buy extra hardware apart from what I have mentioned already. However, if you do think this is a case where the limits of hardware have been reached and that I should go buy hardware, please do explain the benefits to this particular shooting scenario.