As promised, Mina came to the rescue!
Drawing is really fun. I started less than 2 years ago and some people tell me I'm talented cause I did a bunch of portraits of my friends.
Well anyway first of all, pencils aren't that much important. I use hb pencils which are used for writing after I turn the entire house upside down trying to find one of my older b pencils. xD I suggest pencils like 2b, 4b and 7b, nice 'nd soft, nice for shading ( I had 2-8b, lost them all >_>).
But meh, I never used more than 3 pencils for one drawing. I menage with just a single one even if it's lame.
Then, when you shade you need to control the pressure of your pencil. When you do darker shades, press harder and as you back away from the dark point, slowly lessen the pressure. Hold the pencil in kind of a angle so it's smother. It has a lot to do with how you hold your pencil. Find that on google, I read a lot about that in a book someone gave me. I suggest you smudge a little bit with your finger, but just a little, it can destroy the shading. My hand always black when I finish. xP also make sure you shade in only one direction and really carefully.
Where to put shadows...hmmm....easy
Well you're a gfx-er, right? It's just like in sigs, you have a light source. On the opposite side - shadow, darker place. just make some But when you have a highlighted place standing out make sure you show it and leave it white. Well meh.
If it's that hard, at the start watch from a picture when you draw, after a shorter period of time you'll get used to it and it will be a lot easier.
Any questions? x) Suddenly, I feel inspired. Good for me!