Kalin is right about the crate training. I'm trying to remember how it works with puppies... they pretty much have to go to the bathroom every couple of hours. I think it goes by how many months old they are is how long they can hold their bladder (in hours)... or maybe it's however old they are they can hold their bladder for half of the time. Point is... they go like crazy, and crate training is what teaches them to hold it. Because a puppy is unlikely to use the bathroom if it has to sit in or lay in it during the day.
Dogs, especially puppies, are very reactionary creatures. You have to be VERY good about rewarding her for doing well and reprimanding her if she does something wrong, and it's important to do it right away and then just go about your business. Whenever you see her go the bathroom somewhere she is not supposed to, all you need is a sharp noise or tone to your voice. You could say "No" firmly, you could also clap your hands, snap your fingers or just make a sharp "Ay!" sound with your voice. They react to any harsh, firm noises. Whenever your puppy does something well, be very excited, use a soft, sweet, happy voice. You can reward her with treats or petting (like Kalin suggested). But make sure you reward her every time she does well going to the bathroom outside, and that you reprimand her every time you catch her doing her business where she shouldn't.
Training a puppy is about watching them as often as you possibly can and just staying consistent with your rewarding/punishing reactions. Puppies will eventually learn the behavior. Dogs are smart and they pick up on those things. The best advice is to just stay consistent with it and to crate her whenever you have to leave and can't watch her.