Or if you have the balls, (I definately wouldn't) you can go up to someone who looks to be in good shape when they are squating or deadlifting (I'll explain why below) and say "Hey my name is John Doe and I noticed you seem to know what you are doing with free weights. About 6 months ago I was very out of shape (toss in some numbers) and now that I've lost a good amount of fat, I'd like to put on some muscle. I'm not very experienced with using free weights, so I was wondering if you could spare some time sometime and teach me?
The only people that will say no are the jerks, and possibly if you happen to pick someone who is a personal trainer and they aren't able to do it for free. But then I know some personal trainers that help out someone in your position for a few sessions for free.
So why someone doing squats or deadlifts? Cause any yahoo gym rat does bench press from time to time. It is the most common free weight lift for guys. Right up there with curls. If someone is doing deadlifts or squats (not on a smith machine), they at least understand the value of them. Pair that up with someone who looks to be in good shape and you most likely have someone who knows what they are doing.
Also remember that with free weights (and even machines) form is more important the # of reps, # of sets, weight, etc. Form is by far the MOST IMPORTANT aspect of lifting. The reason is because with bad form you risk injury of yourself or someone around you (worst thing that could happen) or you may not make any improvements. So with form in mind, start out very slow. Very low weight. Using the bar only or 10 lbs dumbells depending on the exercise. If you notice, most gyms have mirrors everywhere. While this comes in very hand to check out the hot chicks walking behind you without looking obvious, they are there for a good reason, so you can watch your form. Once you have the form down, then start putting small amounts of weight on until you can only do 15 reps or so of an exercise with good form. Stay at that level until you feel 100% sure that you know what you are doing with the exercise, then you will be ready to begin your real weight training routine. This may happen in 10 minutes (curls), it may take 3 weeks (squats).
Again, if you can just get someone to help you out to learn the proper form and what types of lifts to be doing, that is the ideal scenario, otherwise you should read up on this forum and all over about free weights and how to use them. There is a good site that is geared towards women:
http://www.stumptuous.com/cms/index.php but only about 5% of the damn site is woman specific. Everything else is golden information for anyone that has something to learn about weight training.