To tone the belly, perform one-legged the squat, raising one leg in front of you and decreasing yourself by flexing the other joint.While cardio exercise burns fat in your hip and legs, weight training shades and firms muscles in that area, giving you a more lean overall look. Situps and crunches work the muscles in the front of your belly, while leg lifts and planks work those in your sides and back as well. cutting calories from your diet is also important
For your legs you should try mixing up jumping squats and sumo squats. Combine they will burn your thighs and butt.
Focus on hitting every section of your core, this includes your abs, hips, lower back, and butt.
For abs: planks (side planks, full planks, elbow planks) are great for shedding fat. Try v-ups they're intense but they'll pay off with great gains. Leg lifts (figure 8) workout your abs and hips. Russian twists and oblique crunches work good too. I like visiting ab-workouts-guide.com whenever I need inspiration for new core exercises.
For lower back and butt: glute kick combo and plank with leg lifts will target your butt directly. Hip-ups (aka bridge) and the single leg lift will workout your lower back and butt at the same time giving your booty that nice little lift. Also try the superman (aka locust pose) this exercise will will workout your lower back and butt simultaneously.
You can find most of these exercises in my workout 20x10. It's a bit intense, but check it out for some inspiration for new workouts. Hope this helps, and keep us posted.
Good luck and God Bless!