No offense, but this is a ridiculous suggestion. Grip training is one of the most boring aspects of body training, and the health payoffs are absolutely minimal. Please, do not start with grip training - just jump into starting strength (with your doctors OK if necessary). The kettlebell stuff rickdale mentions are also good.
Grip training should be done when the person is already at a moderate level of fitness, and their grip is holding them back(for example, the thing that stops them from deadlifting more is their grip, or from doing more pullups).
Grip training should be done when the person is already at a moderate level of fitness, and their grip is holding them back(for example, the thing that stops them from deadlifting more is their grip, or from doing more pullups).