When animating, it’s better to restrict the types of transformation that is key framed rather than hitting the ‘s’ key on the keyboard to key frame all the transformations of an object or joint.
To do so, click on the object/joint and select the transformations that you want to key in the Channels Box, then right click select Key selected. The keyed transformations will be highlighted orange.
Before you move the object, click on the Auto Key button () at the bottom of the window. Now every time you move the object, selected transformations will be key framed automatically, saving you from manually right-clicking Key selected each time you move something.
If you want to move key frames later, you can do so in Window => Animation Editors => Dope Sheet by selecting the key frame(s) and middle mouse dragging it left or right. (If you can’t drag them and a white circle comes up where your curser is, hit the ‘w’ key to get into the move tool.) You can also spread key frames out by using the Scale tool and middle mouse dragging selected key frames from where you want to scale. (eg: If you have key frames at 1 and 5, and you want to make them be at 1 and 10, middle mouse click frame 1 in the Dope Sheet and drag your mouse to the right.)
You can also do this in Window => Animation Editors => Graph Editor too, as well as change the speed of the tweens. Here, the dots are your key frames and the line that joins them is the tween. Moving/scaling is done with the middle mouse button, just like the Dope Sheet. You can press the shift key while you move key frames to restrict its movement to just horizontal or vertical.
The default graph uses spline tangents and look a bit like a polynomial graph, so if you had an object jumping (eg: Translate y = 0 at frame 1, y=10 at frame 5, and y=0 at frame 10), it would start slow at the ground, speed up jumping in the middle, slow down again around the top of the jump, speed up as it reaches the middle, then slow down again as it reaches the ground.
The Break Tangent button lets you manipulate the gradients on each side of your key frames. (Say you want to make the fall of the jump faster after it reaches the maximum height.) To do so, select a point on the graph, hit the Break Tangent button, then select a tangent handle and middle-mouse drag.
You can also change the type of the graph using the buttons at the top. For my flour sack, for example, I wanted its moves to be snappy so I selected most of its key frames and hit the Linear Tangents button.
You can view all the transformations that have beeen selected to be key framed, or just one transformation (eg: just the Translate X). If you select multiple objects in the Outliner, you can manipulate the graphs of all the keyed elements in one go, which is handy if you want to shift or alter the whole animation. Hitting the ‘f’ key on the keyboard is a handy shortcut for zooming the graph to fit into the window.