I want to make an object spin very fast and slow it back down to a stop at where it started to spin. As if I have a photo in a video and make the photo spin. So I want to make a video with a spinning object in it.
To animate an object you must use keyframes, a keyframe tells Blender the state of an object at a certain frame. Blender will then interpolate the state of the object through the frames in between the keyframes.
To keyframe a property of an object, simply go to the frame where you want to place the keyframe, set the value of the property you want to animate, hover over the property with your mouse, and hit I.
Keyframed properties will be yellow at frames with a keyframe and green on all other frames.
To spin the object I added a keyframe for z-axis rotation of 0 at frame 0, then one for z-axis rotation of 10,000 at frame 240. This makes the object spin 10,000 degrees over 240 frames.
You can then adjust the interpolation curve in the graph editor.
The interpolation is defined by a Bezier curve, you can select and manipulate the keframes and thier Bezier handles in the graph editor.