The most interesting and common animation should be walking. Actually walk animating is a bit advance technique. However if you only require the basic walk animation with the minimum poses, it should not be too difficult to master.
The following video illustrate how to create a walk animation is very detail:
Basic Walk Animation Tutorial Tips:
Focus mainly on the legs animating. Once the legs animation has been mastered well, the motion of the body, hands, head and other parts can easily be added.
Draw the most important poses first. Most animators called this poses as Extreme Positions. The extreme Positions are the most important positions in the animation.
The middle position between the two Extreme Positions is the second important position of a walk animation. Most animators called this Breakdown Position. In a walk animation, this is sometimes called Passing Position.
Once the Extreme Positions and Breakdown Positions are drawn, the basic animation motions are almost formed. For a smoother animation, some positions are required to fill in between the Extreme Positions and Breakdown Positions. These positions are sometimes called in-between positions. For an animation production, the animators will spend most of their time in drawing the Extreme Positions and Breakdown Positions while the in-between positions are usually done by assistants.
For some animations, the animators only draw the Extreme Positions. The assistants will draw the inbetween positions according to the instruction. The Breakdown Positions will be drawn first, then the other in-between positions will be followed. This is usually indicated with a chart shown on the first drawing.