Yay for kettlebells! Easily my favorite form of exercise. At my box, the standard weights are 53# for men, 35# for women. Scaling down for reasonably fit beginners, men can usually start at 44#, women at 26#, at least for just straight swings. Couple of tips:
- Take the time to learn the proper form of a swing. It isn't difficult, but it does take some practice to get right.
- Learn the Russian-style swing, where the bell comes to around eye-level, versus the American style, which brings the bell fully overhead. The Russian style will give you all the benefits, with the added bonus of not destroying your shoulders.
- Just swing in the beginning. Get good at it. Believe me, just swinging a bell looks pretty easy, until you start.
- Don't use your arms to muscle the bell up. Your arms are there solely to hold onto the bell. All the swing comes from the power generated by thrusting your hips forward. If you find yourself muscling the bell up, try swinging with a T-rex grip (elbows bent, wrists bent down) until you get the hang of it. Note: I don't know if T-rex grip is really a term, it is just what it looks like to me.