How Are Kettlebells Different From Barbells and Dumbbells?
The most obvious difference between kettlebells and dumbbells are the way they are shaped, which results in a much differnt feel while lifting. Kettlebells usually have a thicker handle also which makes them a little tougher to hold on to. The shape of the kettlebell also shifts the center of balance as you lift it meaning you'll need to use a little more coordination while lifting.
Most kettlebell exercises also focus on compound movements rather than isolation movements. In laymen's terms, compound exercises recruit different muscle groups to complete a lift instead of focusing on just one muscle group by bending you at multiple points. Examples of compound exercises are kettlebell cleans, snatches, and squats. An isolation exercise on the other hand would be curling a dumbbell to hit your biceps. In the previous exercises, core muscles, leg muscles, and arm muscles all work together to complete the exercise.
Most people should stick to compound exercises because they stimulate the body the most. Isolation exercises have their place, but they are more helpful for advanced lifters. High rep squating exercises will cause your body to have optimum growth hormone levels and low rep deadlifts will keep your testosterone levels high (Mahler 22). So, unless you're already a monster of strength, focus on the exercises that will hit your body the hardest and make it create the benefitial hormones crucial to supporting a strong and healthy body (Anderson). Don't waste time on the other 80% of exercises that will bring you only 20% of the results (Pareto). Keep it simple and try it out. You'll stimulate more muscle growth and be glad you did it.
Sources
Anderson, Jeff. Compound Exercises. Critical Bench. 2008 Mar 11 [http://www.criticalbench.com/compound-exercises.htm]
Mahler, Mike. The Aggressive Strength Solution for Size and Strength. Mike Mahler, 2006.
Pareto Principle. Wikipedia: The Free Encyclopedia. 2008 Mar 11 [http://en.wikipedia.org/wiki/Pareto_principle].