In what parts of the heart do you find oxygenated blood and in what parts do you find deoxygenated blood?

The right side of the heart contains oxygen-poor blood, as it has just returned from the body, and the left side contains oxygen-rich blood, as it has just returned from the lungs.

Remember that when you are looking at a diagram of the heart, the sides are reversed from how they are in the body itself. The blue chambers and vessels indicate oxygen-poor blood flow and the red chambers and vessels indicate oxygen-rich blood flow: