First off, relax, you won't bulk up and look like a man, you simply don't have the testosterone for it. If a man and a woman lifted exactly the same equivelent amount of weight for the same reps, the man will develop lots more visible muscle than the woman. She'll get strong, but she won't bulge.
Next, you need to work everything. Ok, your legs are important, but without an equally strong back, you'll find yourself in trouble and prone to injury.
The basic lifts for best results are squat, deadlift, bench press, stiff leg deadlift, military press, pull-up, dips, bentover row, lunges, wood chopper, hyper-extensions.
A great site to show you how to do any exercises you don't know is
ExRx (Exercise Prescription) on the Net
Ideally, I'd go for three sets of eight reps per exercise. Make sure you have at least two or three days between sessions on a particular muscle.