I totally agree with what midwestj is saying. Muscle on us ladies rarely looks bulky (barring certain health problems/hormonal imbalances) -- your time is better spent focusing on eliminating some of that body fat overlying it. Ironically, for females, doing what guys do to "bulk up" has what I would consider an opposite effect on us since lifting weights challenges your body in ways that result in major calorie burn both during and after your work out. That interval training-type cardio others have mentioned has a similar effect. You will lose body fat and retain muscle mass. Additionally, the more muscle you have, the more calories your body burns naturally -- so instead of having to eat less and less as you lose weight the "conventional" way (i.e. low calories, lots of cardio, etc. which results in loss of both muscle mass and body fat resulting in a slower metabolism) your body will continue to need a lot of energy (calories -- yum!) to maintain its new leaner, meaner form. Instead of focusing on "weight loss", try thinking about "fat loss" -- this means cutting body fat while preserving (or increasing!) your metabolism. In my experience, this is way more delicious than feeling guilted into choosing the salad over the burger or, worse, having to pass up a fun night out.
Also, just a note of reality in here, girl to girl -- I saw that you wrote that you dislike the shape of your body, and this worries me. I can relate in some ways, being a short "curvy" girl myself -- sometimes I feel like I'm all boob, thigh and hip and not in a good way! A person cannot change the underlying dimensions of your body or the shape of your muscles no matter how hard you work out. You cannot have a "dancer's body" by doing a dancer's workout (as I saw on a Shape or Fitness magazine lately) and your muscles cannot become longer or leaner than they are genetically predetermined to be. Because you cannot change these things (i.e. no matter how hard I try I will never, ever have a body like Kate Moss), you have to work with what you have and realize that this is not a bad thing! For me, that meant becoming less jiggly (lol), stronger (Here's me: "Like, holy crap! I'm pretty strong! I could get REALLY strong, like stronger-than-some-guys-at-my-gym strong!"), and faster than I was previously. I say this with all sincerity: realize you already have a good base to start from. Don't try to change it into something it can never be, but morph it into something that makes you feel better about your badass self!
(sorry for letting this get so long, its just something I've been thinking a lot about lately