The general guidelines for picking your kettle bell are as follows:
Most women who are beginners would usually start with an eight-kilogram or a 12-kilogram bell, depending on their training age, and by TRAINING AGE I mean how long you've been training, not your actual chronological age.
So for example if you've been training for several years now and are familiar with the basic exercises of squats and dead lifts, lunges, rows, and presses, then again, depending on how strong you are you may want to start with a 12-kilogram bell, which would be the heavier for women.
If you're an absolute beginner then you should start out with an eight-kilogram bell or even a four or a six-kilogram bell, depending on how confident you are with lifting weight.
If you're a male beginner to kettle bell training but you have experience in the weight room, you can get away with using a 16 to 20-kilogram kettle bell.
If you're an absolute beginner then I would suggest, depending on your strength levels, again to start with a 12 or a 16-kilogram bell.
REMEMBER – each individual is different and we learn and adapt to different movements and exercises at our own pace, so put your ego away and start out SLOW and UNDER CONTROL without being too ambitious with how much you think you can lift. So those are the two starting weights that I would suggest.
Again, females, eight to 12 kilograms, again, depending on your training age; males, 16 to 20 kilograms, depending on your training age. Those are the starting points for both.
Let me know if there are any other questions I can answer for you. Train safe and have fun!
-Chris Lopez, CTT, CSCS
Author, TT Kettlebell Revolution