01: Drawing With Shapes
There is one general rule I always try to follow with art,
Start Simple! I find that if you let yourself bocome focused on the details at the wrong times you will ignore the other elements, and the whole image will suffer. Focusing on details is usually the cause of incorrect proportions, perspective problems, and all sorts of other things that can ruin your project. So, start simple!
In this lesson we will learn to see the shapes that make up an object, and how using those shapes is helpful when drawing.

As you can see in the image above I used 2 shapes to draw this lamp. First I drew a circle, then a triangle, the two most basic shapes in the object. Next I cut the triangle to make it match the shape of a lamp shape, and added detail. Everything you will ever draw consists of these kind of simple shape relationships. You can also use basic shapes to help with proportions.
As you can see here I used the basic shape of the head to measure out my superly proportioned guy.

I know he should be about seven heads tall (regular people are more like 6, but this is a really awesome guy, so we will make him 7 for added super-hero like coolness), so I laid out 7 heads. I also used basic shapes (hello cylinders) to place other body parts. This way I know the proportions are looking correct before I make him look all muscle-y.
As you can see in this second image I used these basic shapes to help me finalize the pose. Once again this made me focus on the proportions and relationship of the shapes before I got into the details. Once I had this stage complete I was able to start refining the drawing by removing un-needed lines, and adding detail (see finished image below).
Make sure you understand this principal, especially when drawing from your head. You need to be able to think in simple terms to be able to imagine how things should look when you don't have a good reference to look at. Not only will it improve your ability to draw and keep things in proportion, but it will also help when you get to the stage of shading, and other similar things.
Next: Lines