An interesting rule I have learned not too long ago is to invision an upside-down triangle when you're drawing the torso.  The sides should be twice the size of the base.  This helps you with a couple of areas in the torso.

Point A, at the corner of the triangle's base should be the point of the shoulder.   That should be where the shoulder bone ends.  (Though, like in my example, the arms can move out a bit more.)

Point B, about 3/5 the way down the side, should be where the hip ends, and the body starts to move towards the waist/buttocks area.  (If you're laughing at me writing "buttocks," grow up.  ^_^  Ok, I laughed, but still...) 

Point C, the tip of the triangle, is where the crotch begins.

Of course, these points can be mirrored to the opposite sides.  And this can be used at a 3/4 angle of the body.  You just have to skew one of the angles towards the viewer

Note: This is only to be used as a guide for the female torso.   Remember--a woman's body is supposed to have no straight lines; only curves.

Are the breasts really the holy grail of drawing a sexy character?  Of course not completely, but drawing them right has always been a trouble for many artists.  Expecially men.  (Including me ^^)   Maybe they feel perverted practicing drawing them?  Or possibly they've never seen any.  *Cough Cough*

The main point being...

The base starts below the armpit area.   In fact, the breasts grow from the armpit line.  There is also a space between the two bases.  Remember that.  From the base, the fat of the breast expand in ever direction, but mostly downward. Of course, when you consider putting a bra on your character...  (I hope you do dress her...)   A portion of the gravity could be pulled back, so the end result would be somewhere between my bad and good example.

It's a fact of psychology that men generally regard women with a hip to waist ratio of 7 (hip) to 10 (waist) as being "sexy."  Ratios like 8 (hip) to 10 (waist) work well.  I wouldn't recommend going below 6, because than she looks anorexic. 

Please, don't get out a ruler.  It's just a guide so you can just guestimate.  There are more important things to worry about, such as the face of the character.

And while I'm here, I may also point out that, yes...  there is a space between the two legs.  The crotch is something people beginning to learn about artistic anatomy forget, not jsut on female bodies, but male bodies as well.

Like from the front view, you can also see the 7-10 figure on the back. 

Now, think in terms of 3-Dness.  The buttocks is coming out of the normal plane, so it will overlap near the bottom where gravity is pulling down on it.  Also note that you can see part of the crotch.   The legs branch out near where the crotch meets the buttocks    (o_O Getting a bit graphic here, eh?)

You shouldn't just conquer the front of a character design.  The back, as well as the side, is just important if you're trying to express a scene in your picture.  As mentioned above, you can still see the seven-ten figure on the back, and the triangle trick works just the same.   The difference is...  it's the back.  You basically draw the body in the same way, except you don't put breasts on it.  (I hope you knew that before you read what I just wrote.  o,o)

There are a few lines to signify bumps on the back.  Mainly, they're simplified to the spine and the shoulder blade. 

The side view is a bit strange.  It follows it's own rules.  However, even on the side, you can make out the distict hourglass shape of the body.  Not only does the waist become concave on the front view, but the side view as well.

I can't think of many more tips for the side view, because it becomes something you learn over time and practice.  Try drawing the sideview like the one shown, and make observations.

The legs can be split into three parts; the thigh (top of the leg), the calves (lower part), and the feet.   Proportional-wise, the calves are longer than the thighs.  Though sometimes in manga, the two are exactly the same.  It may be some type of a style issue.

With the legs, there are plenty of curves you must learn to get right.  The side profile of the leg has a much more curvaceous figure than the front view.  On the calves, there's a larger amount of fatty tissue towards the knees.  On the thighs, the curve is not as noticible than on the calves.  The knees can simply be a slight depression. Don't make it look like the legs have just been near strangled to death.

The Toe

Yeah, yeah...  it's a foot, so what?  Ah, yes, but it's harder to draw then you may think.  It's about as curvaceous as the rest of the body.  Just look at your own foot when I describe every crook and nanny.  It's actually rather complicated.  Then try to draw it.

The foot sort of branches out from the leg.  It slopes down at a slight angle, increasing more until you get near the toes.  On the bottom of the foot, you have the calcaneus bone, which is that large bump at the back of your foot.  Above it is the ankle.  On the side facing in towards the body, there's a large pyrmaid shaped bone.   On the opposite side--the side facing away for your body,--is a smaller pyramid that is lower down the foot than the larger one.  The foot isn't flat, obviously.   The foot becomes concave and curves inward towards the foot.

And the toe is something you must think twice about.  It's not simply stubs coming off the foot.  The toe, like the finger, bends in 3 joints.  The first is a little bit off the toenail, followed by one about 1/3 the way down from the first.   And finally, there is one that connects the toe to the foot.

It's important to see the shape in the arm.  It's actually much more simple when you look at it as two ovals rather than a mass of flesh around a bone.  (Though, it's better to think of it as both.)  Draw two ovals over your basic outline of the character.  The upper arm is a bit thicker than the lower arm.  And the lower arm is half an oval, with the other side sloping down slightly to connect to the hand.  This gives you a good base to work off of.

Remember, if the arm looks too thick, you can always redraw parallel lines and erase the extra.  A child's arms are chubby, but a full grown, slender woman more along the lines of longer, thinner arms.   

For the bent arms, I used the same process as the straight, I drew two ovals as the base.   Now, when looking at the arms from this angle, there's generally a little mound on the outward side of the arm that forms due to the squeezing the muscle and fat as the arm is bent.  Also, the elbow isn't a perfect half-circle, nor is it a box.  It's a bit of both, going down at a straight angle where the bone is, and curving around.

Expect a hands tutorial to be up within a few weeks.  It will be too large to fit in this little box.  For the mean time, take a look at Wynd's gallery of hands.  It's a good source of hand models to draw.