Oh almost forgot the important question regarding learning lighting. There are a few rules to remember regarding lighting which is where i feel its best to start. When setting up a lighting scheme, it's all about you making decision as a photographer. To make these decisions, remember this very important thing... you must observe light. It still amazes
me that some photographers set up lights totally "blind" based on lighting diagrams or that they have learned that the main light should always be exactly here, at this height and aimed here and the kicker yada yada yada. Instead they could open up their eyes and look at the shadows and the highlights and determine if this is what they want. If you did this, it should be impossible to accidentally take a flat boring picture ;D
The rules we all abide by can be summarized like this: shadows and highlights, shape and softness. Lets start with shadows.
The softness (how blurry) of the shadow is determined by one major factor, how big the lightsource is in relation to the subject. Quick example using the sun; on a clear cloudless day you will have extremely sharp shadows because the light now is a very small pinpoint source (ie. the sun). On a overcast day you will almost not have any shadows, simply because the entire sky now acts as the lightsource (with the pinpoint behind it
and this is thus a very large lightsource.
Now to translate this into studio lighting, you can use softboxes, diffusing screens, umbrellas, reflectors, etc. to shape the light, but the shadows will still be mainly affected by how large the source is in relation to the subject. If you take a small reflector and put it really close, it will create a soft shadow compared to putting it further back. If you take a huge softbox, and move it far away, it will also create a sharp shadow, since even though it's physically large, it's small in comparison to the subject. So remember this first rule, large lightsource = soft shadows, small lightsource = sharp shadows.
The shape of the lightsource will also affect parts of the shadows in one way. Some lightsources may create multiple lightsources, for example umbrellas (especially cheaper ones) can look like it's one lightsource per segment and this will show up in the shadows as multiple shadows. This is not a rule in itself but its' good to be aware of it.
Next we look at the highlights. The highlights have shape and falloff aswell, the shape being the reflection of the lightsource on anything shiny (like skin, eyes, clothing, teeth, etc). So do you want a square reflection, or a round reflection etc. It will look different on the cheekbone, the eyes, the forehead, the nose etc. Also different brands and quality of softboxes may affect the shape (and falloff) simply because they may not be lighting the softbox evenly. It pays to have quality here.
The falloff of the highlights are ruled by the same thing the shadows are. Small lightsource = sharp highlight, big lightsource = soft highlight. So if you use a large softbox for example close to the subject and expect to see sharp highlights on the cheeckbones, you will not get those
You could however put in a secondary light with a smaller source just for the highlights.
Now those of you who havent' fallen asleep already will note that i havent talked about the midtones (the areas between end of the highlight and the start of the shadows) but they are the areas evenly lit by whatever lightsource you use. So well not really that much to say about them.. they are lit. It's in the highlights and shadows the fun part comes. This is where you can create shapes and form with the light.
A little note though on using hard sharp shadows and highlights (aka. small lightsources). Every skinpore and blemish has a shadow and a highlight, this is how we see them. So accentuate the shadows and highlights and they will pop out aswell which may result in hours of retouching to make it look smooth. So make sure the makeup and the model is correct for a shoot with hard lighting ;D
The most important thing to conclude is what i said in the beginning, observe the light. If you are using flashes (or continous light), move it around, watch how the shadows and highlights move around, move it back and forth, watch how the shadows focus and unfocus. This will teach you a lot more about lighting than any book or video (or forum post) ever can. And take it a step further, observe light as you move around out in the world, watch how it plays through a window, reflected of water, bounced of a wall onto someone walking by, etc. When you start doing this and applying it to your photography, then you will start to consider lighting a fairly simple thing ;D
Hope my long posts helps ;D