Great info from all the previous posts, but also i would specify what your goals are and what you want out of your body. Do you want size, or toned or just to lose weight because all require completely different workouts, so to sum it up take the advice of the others and hire a trainer at first but make sure you know what you want so you can make the most of your time with the trainer because their not exactly cheap. Anyways good luck.
MATT,
Well you are repeating a little bit of a misnomer. To lower your fat/weight ratio (I say this because it is not about losing weight but looking and feeling good - muscle weighs more than fat) the more muscle mass one has the more calories their body burns when the muscles are at rest. This in itself inceases the speed of one's metabolism. Add to this an effective cardio-vascular workout and you have the makings of beneficial exercise. It is also a misnomner that bigger weights necessarily translates into more bulk and lighter weights are more successful for toning. Toning is accomplished when our calory intake is equal to or less than the amount of calories we use in a day. Actually bulking up is the result of feeding the muscles the right amount and combination of amino acids coupled with great breakdowns of muscle tissue and rest.
At any rate, I do understand you point and clearly defined goals will help an individual develop a succesful regimen. But the most successful programs involve a multidimensional approach to excercise, nutrition, and rest.