Should I do heavy lifting? Where do I start? Help!

You could always start with basic bodyweight exercises. Squats, pushups, etc. You want to be able to settle into a good squat position before you even put a bar on your back.

Resistance training (i.e. lifting heavy) is always a good idea for any exercise program.

Look into the book, "New Rules of Lifting for Women." I also recommend Mark Riptoe's "Starting Strength." I'm a huge proponent of building up a good foundation of functional strength with low rep, high weight compound lifts. These aren't lifts to bulk you...these reps are not in they hypertrophy range, they are in the strength training rep range but also go a long way in changing body composition, especially if you're new to the weight room. These types of lifts (squats, bench press, dead-lifts, overhead press) work the biggest muscles of your body to their fullest extent for optimal results.

If you don't have access to the equipment and can't get to a gym, look into resistance bands and/or body weight stuff. Nerd Fitness has lots of good ideas.

http://www.nerdfitness.com/blog/

The term "lifting heavy" is most often synonymous with the big compound lifts I noted earlier...that aside, it is important to do some form of resistance training regardless of where you are in your weight loss journey. If you aren't using your muscles, you're losing your muscles. In the absence of resistance training while eating at a calorie deficit, you will lose a lot of muscle as well as the fat.

Heavy lifting has helped me shed fat, and shrink in inches, quite a bit. I started with a program (also a group here) called Strong lifts. It's the basic compound moves. Wishing you many strong days ahead!

yes it will definitely help. heavy lifting and strength training will ensure that your body predominantly burns fat while you lose weight and not fat and muscle. the result is that you 2will look as if you've lost more weight than what the scale shows

start with body weight first to make sure you have the form correct and then gradually start adding more weight.

look into programs like starting strength, strong lifts and wendler 5/3/1

Start lifting now. Pick a compound lifting program like Starting Strength, Strong Lifts, or the New Rules of Lifting for Women. You can still do cardio, but you don't need to do a lot of it (you don't need to do it at all, honestly, but I still like to).

Calculate your TDEE and subtract 20%. Eat that level every day. Aim to get at least 0.8g of protein per pound of lean body mass. Set your fat and carb macro goals accordingly.

Yay, friend!!!!! Welcome to the club!! I'm looking forward to seeing your progress. Oh yeah, if you're ever unsure of how to do certain lifts, YouTube is a really good tool. Also check out some of the groups in the community forum:

http://www.myfitnesspal.com/groups/home/12919-girls-who-lift-the-guys-who-spot-them
http://www.myfitnesspal.com/groups/home/4601-stronglifts-5x5-for-women
http://www.myfitnesspal.com/groups/home/12971-nrol4w-spring-2013
http://www.myfitnesspal.com/groups/home/102-new-rules-of-lifting-for-women-nrol4w

You should absolutely lift. Women with muscles is quite "dreamy." Look up womensfitness.com . They have planned out weight lifting programs for women from beginner to advanced. Good luck.

Start lifting now. Pick a compound lifting program like Starting Strength, Strong Lifts, or the New Rules of Lifting for Women. You can still do cardio, but you don't need to do a lot of it (you don't need to do it at all, honestly, but I still like to).

Calculate your TDEE and subtract 20%. Eat that level every day. Aim to get at least 0.8g of protein per pound of lean body mass. Set your fat and carb macro goals accordingly.

Quoted because good advice bears repeating. Nothing reshapes the body like building strength, lean mass, and a good diet to fuel the fire and carve off fat.

Just pay very close attention to movement quality and form when performing compound lifts. There are those who claim that squats are bad for the knees, or that overhead presses are risky for the shoulders, etc; these things are only true if poor form is used, or there are pre-existing mobility issues.

Stretch thoroughly, use full range of motion, pay close attention to form (it can be daunting at first, but hang in there), and you'll do fine.

Heavy lifting is definitely worth it. Work on form first. You can't go wrong with squats and deadlifts.

What about cardio? How much of it would I need to do? And how much of a calorie deficit?

The lifting question looks to have been answered. With regard to cardio and your deficit. With >100lb to lose, you are good with setting your weight loss to 2lb a week - when you have lost a decent amount of that, you will want to re-assess and drop that down to 1 1/2 and then 1lb,

Do as much cardio as you want (within reason) to help create that deficit.

If your trying to lose weight I wouldn't advise you do heavy lifting because that will put on muscle weight which will make the scale go up and not down.
I recommend you do lighter weights and more reps.
That's what I'm doing.

Ignore this.

It is a good idea to change up the routine, but try to keep using a challenging weight for you.