I'm not quite sure what Cliff's Notes you read, so I'll just start at the beginning, and you can pipe up with questions as we go to steer the discussion in the direction you are interested in.
First year biochem involved lots and lots of drawing chemical structures by heart <Zzzzz> I'll spare you the details.
The basic building blocks of biochemistry are the four groups main groups of macromolecules:
1) Carbohydrates -- alcohols, sugars, and chains thereof
2) Amino Acids -- which form proteins
3) Nucleic Acids, which form things like DNA and RNA and ATP
4) Lipids, which include fatty acids and "fat like" substances, including triacylglycerides, phospholipids, cholesterol, plasmalogens, wax, and more.
These are the main actors in the metabolic pathways.
Metabolism has a yin and a yang: catabolic processes (break components and molecules down, generally produces energy usually in the form of ATP or heat) and anabolic processes (build new components, generally requires energy).
In biochemistry metabolic pathways are usually described using a very large amount of chemical structures and a very large number of arrows.
Here is a small series of videos that explain some of the basic metabolic pathways that you might encounter in Biochemistry 101:
Professor Fink Explains Cellular Respiration
Also relevant to the discussion at hand:
insulin's role in blood sugar regulation and synthesis of fat
I would also highly recommend watching Sugar - The Bitter Truth for more details specific to the carbohydrate story.
Like I said -- ask away to guide this in the direction most helpful to you!