This is good, but I disagree with the rest. The chain should not be "tight" when you're finished. It should be as tight as possible without binding at any location. Snug the bolts to tighten the wheel, then slowly spin the pedals to make sure it's not binding. You can feel when it gets tight. Move the wheel a little closer to the frame until it feels smooth at every point. It may sag a little, but it should not be loose and floppy.