Quickly add keyframes to active objects by pressing F9. This will keyframe the position, rotation and scale of an active object, but if you are trying to focus on a single property you can add a keyframe by Command + Left Clicking on the Record button (that little gray circle next to nearly every property in Cinema4D). F9 is very useful if you are roughing in animation for a fast and easy preview. You can always go back and fine tune your animation curves after setting the keyframes with F9. Enjoy!