I think training only for explosiveness is useless, its much better to just stregnth train your core muscles. I tried doing just a bunch of explosiveness training for lacrosse and it felt like I got nothing out of it come gametime. If you still want to try it this book "Core Performance" by Mark Verstegen has some good ideas and exersizes for agility and explosiveness. I dont know if I would follow his workouts down to the sets and reps though, just do what works for you instead.