This is probably the most frequently asked question when it comes to lifting weights, so I thought I would address it again. In general, if you are a beginner, then one to two sets of 12 to 15 reps will begin to build the foundation. Later, after you’ve established some consistency with your workouts, and your body has begun to adjust to the weights, you can begin adding in another one or two sets. After a few months, you should decide if you want to train for endurance (minimal muscle mass), strength (moderate muscle mass), or power (extreme muscle mass). Endurance athletes will benefit from 3 or 4 sets of high reps with low weight (i.e. 15 or more reps). If you want to build some strength and muscle tone, then you should aim for 3 or 4 sets of 8 to 12 reps. If you are a power lifter and/or want to add bulk, you should lift heavy weights for less than 6 reps with multiple sets. Your weight should be heavy enough so that by the last rep, you should just barely be able to accomplish it while maintaining good form (i.e. don’t cheat to get the last rep out). In other words, “light weight” is a relative term. Most women I have met tend to go too light for most things and are scared to lift “heavy” because they’re afraid they’ll get “bulky”. This just doesn’t happen to most of us, because we don’t have the amount of testosterone to allow us to get bulky. Granted, some body types are bigger and more muscular than others, but that never means to avoid weights! We all have to work with what we’ve been given. I hope this helps answer the question. Let me know if you need any more help.