I'm female, currently weigh 220lbs, and am 5'7". Last year I lost 40+ lbs doing only cardio 5-6 days a week and reducing my calories. After turning 21 I slowly gained it all back plus about 25 lbs. This week I started back up again. I eat 1400 calories a day on the days I go to the gym; 1200 on the days I don't. Right now I walk at a fast pace on an incline on a treadmill for 60 minutes 5-6 days a week. I'm quite ignorant when it comes to weight training and consequently have always avoided it. I would like to incorporate weights but don't know where to start. I would prefer to continue doing cardio at least 5 days a week, but would like to add in weight training for 15-30 minutes before or after the treadmill, depending on which is better. What types of machines should I use? How many reps? I certainly don't want to bulk up but would like to keep some muscle as I lose weight. Any advice would be greatly appreciated.

Have you read the stickies?

Which stickies, specifically, are you referring to? I've read most the threads here for the last two years, and if I'm not mistaken, when someone usually asks for advice you usually ask them for their stats, which is why I made my own thread. Most of the stickies I read contain very broad advice and I wanted something that would specifically work for me.

you said that you were very ignorant when it came to weight training.

The stickied threads i the exercise forum - will help get rid of some of that ignorance and will give you a very good starting point..

Do ask questions on things you don't understand after reading... but do spend the time reading them becuase the words and the videos are helpful