^ I wouldn't say "never," but without years of dedication towards the goal of being huge, favourable genetics, intelligent exercise and nutrition programming geared towards the goal and probably some black-market vitamin T supplements, it's not realisitic to think that it would happen. Simply put, out of the very few women who actually desire to have massive muscles and take the "get huge or die trying" route, most will be in the die trying category. Kathleen, since you won't be trying to get huge, it's not something you need to worry about.
I agree, 3 days a week of lifting starting out, and if you have to start with machines do it, but free weight exercises are better for a myriad of reasons.
Ideally, whatever program you end up doing should include squats (with hips going to or below parallel with the knees at the bottom), hinge movements (such as deadlift and Olympic lift variations that involve pivoting around the hips), horizontal pushes (such as bench press and dips), vertical pushes (any movement in which you lift a weight overhead), horizontal pulls (most rowing variations) and vertical pulls (such as pull ups, lat pull downs and upright rows). If you have one exercise from each of those movements in your program, and you practice good form on each exercise, focusing on technique and progressive overload (increasing either weight lifted or volume as often as safely possible), you'll do well.
There are several decent programs in the Weight Training stickies, and I've also got a good, simple beginner's strength program written up in the Young Athlete Development section (also in the stickies). The program, obviously, is targeted at novice athletes who need strength and conditioning for their sport, but it is just as suitable to someone whose "sport" is training in the gym.
The program ideally has you training 3 non-consecutive days per week (I strongly recommend against training any more frequently than that while on that program - you'll build up too much fatigue and it'll stall your progress), although 2 sessions a week is permissable if sport/conditioning requirements demand a reduction in strength training. It's an A/B split, meaning that you train the whole body every time you enter the gym, but you have 2 different lists of exercises that you'll do, and they are:
A: Squat 3x6-8, Overhead Press 3x6-8, Power Snatch 5x3-5
B: Squat 3x6-8, Dips 3x6-8, Pull Ups/Chin Ups 3x6-8
For each exercise, you do your warm up sets, then 3x6 (or 5x3 for power snatches). Every time you do the exercise, you add 1 rep onto each set (so you move up from 3x6 to 3x7, and then next time from 3x7 to 3x8). Once you get to 3x8 (or 5x3) you increase the weight by the smallest amount possible and return to 3x6/5x3. Ideally, this would have you adding 5kg/10lb onto squats, 2.5kg onto overhead press and power snatch, and 1.25kg onto dips and pull ups, every 2 weeks.
