Over at www.art-classes.com I took a class called 30 Days To More Confident Sketching.
One day at a time we watched videos and learned to sketch with only graphite pencils in a varying selection of hard/soft leads. This gives the range of lights/darks for highlights and shadows.
For some lessons there were photos provided to draw from but in most cases I researched to find similar subjects with different layouts so I could practice what I had learned rather than just copying the instructor stroke for stroke.
These are the pages in my sketchbook: