If your has multiple inputs, then, I would simply connect the vcr to one of those inputs using the composite cables (red, white and yellow), and the cable box on a separate input as well. If your cable box has composite outputs or S-Video (even better), then I would hook up the cable box to your tv using those connections. Preferable S-Video if your cable box has the outputs, but if it doesn't, then use the composite outputs.

Hope this helps