One of the best exercises to build lower-body strength and challenge your entire body is the Dumbbell Deadlift. Although many athletes flock to the standard Deadlift, don't discount the value of its dumbbell counterpart. (Learn how to get strong with the Deadlift.)
Compared to the barbell variation, the Dumbbell Deadlift is easier to perform for beginners and for athletes who lack mobility. You can get your body into the proper lifting position with your back straight, hips down and knees bent. Also, the position of the weight closer to your sides encourages you to drive up with your hips and then your knees—an essential aspect of traditional Deadlift form that is often ignored. (Master the conventional Deadlift.)
I recommend the Dumbbell Deadlift for anyone new to the weight room. You will quickly learn the proper Deadlift movement pattern, as described above. You won't be lifting massive amounts of weight, but you will be building a foundation of strength to progress to the more advanced variation.
Try adding the Dumbbell Deadlift to your workouts once or twice per week. Use it as a supplemental exercise after your main core lifts, such as Squats, Lunges and Cleans.