It is good you have your diet in check. Just get to feel what your maintenance amount of calories (how much you can eat and not gain/lose weight) are then try to take in a little less…you will get the idea how your body responds and what and how much you need to eat. Just don’t try to rush it…losing too much weight too fast means chances are you are losing way too much muscle. I always use a rule of anything over 10lb’s a month (for someone who isnt too fat/big) is a decent rate where you are minimizing muscle loss.
As for the weight lifting do not be scared like most females about the whole I dont want to look like a bodybuilder/bulky thing. Just stick to moving somewhat heavy weight for 12-15 reps…and those are hard reps not just going through the motion reps…the last couple should be hard. Try to do compound movements. For example bench press, rows, shoulder presses, and chin/pull ups are good for upper body. Learn to do squats the correct way with a bar (can also do lunges, one legged squats there are a ton of varieties) and stay out of the smith machine. Most people don’t realize it but doing heavy compound movement requires more muscle to work together and in turn will burn more calories. You wont burn as much as doing cardio but you will burn a lot more than most think. If you like to keep moving in the gym you can “superset” things like bench press and rows…where you would perform you bench press set and just catch your breath then go straight into a set of rows.
This is just a very general overview to get the feel of it…feel free to ask any specific questions.