Don't worry about bulking up-- women don't have the hormonal genetics to build bulky muscle like men. In fact, strength training should be an important part of your exercise routine as the lean muscle you DO build will scuplt the gorgeous curves of the female body hiding underneath layers of fat. Furthermore, muscle is metabolically active, meaning that it burns calories continuously (even while sitting) whereas cardio's effects only last approx. 24 hours after your workout.
Start with a 20 minute warmup on the elliptical, and then increase your resistance and pace for another 20-30 minutes. Then head on over to the circuit area to wake up the muscles in your upper and lower body. If circuit training is not for you, squats, lunges and crunches will work great on all the "trouble zones" women complain about.
Stretching feels amazing after a good workout, and they always have posters on the walls in the gyms to follow. Stretching will reduce soreness and increase flexibility. You'll notice a difference in the mirror and how you feel in less than 2 weeks!
Have fun with it!