Try to remember that the right half contains venous or impure blood and the left half arterial or pure blood since that blood has been through the lungs. Our teacher made us learn the route inside out so that we could start at any point and get it right. it is just a loop. You can start anywhere if you know what each little parts job is.
So here you go... inferior vena cava, superior vena cava, right atrium, tricuspid valve, right ventricle, pulmonary semi-lunar valve, pulmonary artery, lungs, pulmonary veins, left atrium, bicuspid or mitral valve, left ventricle, aortic semi-lunar valve, aorta, then out to the arteries of each organ, arterioles of each organ, capillaries of each organ, venules of each organ, veins of each organ, and back to the inferior vena cava.
It helps to write them on index cards and mix them up and put them back in order over and over starting at different points each time. Once you learn the loop you are golden no matter where you start out at. Good luck.