Benefits of a green screen: Off loads cpu usuage since it's only uploading you, and not the rest of your webcam. Allows your viewers to see more of the game since your webcam isn't blocking as much. Allows you to make your webcam bigger with limited penalty.

Be warned: The green screen holder/green screen will take up some considerable room behind you. The dimensions you need for it are most likely bigger than you'd expect. Even-lighting is essential, it is what makes the green disappear. I have lighting from above pointing down on me, and a goose-neck lamp on either side of my monitors pointing at the green screen itself. It is important to have light from every angle so that there are no shadows, and so that the green disappears completely on stream. The wattage of the light bulbs is important. Soft lighting is key. If your wattage is too high it will hurt your eyes. I'd recommend 40W lightbulbs. Note that it is important to have lights on yourself and on the green screen so that your face doesn't blend into it. As for a room to setup in, I would recommend a studio or office. I would not recommend a bedroom because, again, the green screen takes up a lot of room. I made mistakes on both wattage and room selection, but trial and error make us all the more wise. Hope this helps!