I was watching the morning news today and saw a segment on Boot Camp and I have to say that I was a bit disturbed. In one particular section nearly everyone performing a squat was performing it incorrectly. As a corrective exercise specialist, I take great care in making sure all exercises are performed in the proper alignment. Proper form and alignment while working out is essential to gaining strength and looking and feeling great. If you repeat exercises with improper form, you are actually intensifying your imbalances and dysfunctions, causing more harm than good, increasing your chances of injury.
Are boot camps high calorie burners? Yes! Can you lose weight? Yes! Just beware of fast-paced, high-intensity workouts where the instructor doesn't give much "instruction". If you don't know exactly how to do an exercise, then ask! Do your research and make sure the class comes with great referrals.
...and start out slow if you are new to fitness! You don't want your gains to come with unwanted aches and pains!