It is possible to hurt yourself with a kettlebell, but it does take some work. The important thing is to start with an appropriate weight. I would suggest going to a fitness store that sells only exercise equipment because the salesperson will be more knowledgeable about the kettlebell and will be able to assist in the selection of one or two for you. Depending on your gender and fitness level a kettlebell might range from 5 lbs. to 50 lbs. or more. The salesperson should also be able to give you some basic instruction and possible a wall-poster with the movements.
One of the reasons the kettlebell is so effective is that it involves multiple muscle groups with each movement, especially the legs and core. The legs are the largest muscles of the body, and because of that you will impact a larger percentage of your lean muscle mass with exercising of the legs alone.
Below, you will find some videos I linked to from YouTube of some kettlebell workouts. You can find plenty others that you may prefer over these. Your period of resistance training should last at least 20 min. preferably 30, and you should do this twice a week. Your body is awesome in general, but especially in adaptation and so it’s helpful if you can change workouts from time to time, having 3-4 different ones that you can alternate with.
Two minutes: watch this one first!
This short video shows you the proper way to lift a kettlebell so you don’t strain your back. You will see why it is such an excellent form of resistance training.
Eight minutes
This is a good workout for a beginner with a lighter weight and includes a cool down.
Thirty minutes
This is an excellent complete workout. The first minute is a review and you can stretch, but then it starts with a warm up before getting into the exercises. I would work on the first two videos, and at least do the first one, above, before starting with this.
8 minute video; BUT is a 30-40 min. workout: Advanced
This guy, Funk Roberts really likes his kettlebell. You can tell from the way Funk looks that this is an extreme workout not for beginners, but with a lighter weight (at least at first) and after a few weeks (at least) of experience, it is something you may want to try.
All of the links on my site to videos and images and articles are beyond my control, but I placed the links because I felt they held value upon my review of them and I see no need in re-inventing the wheel. All of these folks have similar interests and objectives to our own, relative to fitness and health and I appreciate the effort and skill involved in their making this information widely available. Cool folks.