Animation Tips for Beginners Part 1

Well, I'm not very far into A Boy and His Blob yet so I'm not going to review that today.  Instead, I think I'll start giving little bits of advice for aspiring animators.  I do not claim to be an expert by any means (because I'm not, awesome as I may be) but these little tips will give you a nice head start on your first year.
First off, get familiar with the principles.  Timing is the biggest principle of animation and coincides heavily with all others.  Most college courses begin with you animating a ball bouncing (for my class, we had to animate a ball bouncing in from the left of the screen and eventually coming to a stop at the right) and they do this because it is a simple and very effective way to get your head around showing weight and velocity when animating.  To work out the animation, you would first draw your plan; draw the arcs the ball is going to follow.  Then, draw ticks on the arcs where the drawings will go.  This is where you add in the timing by ensuring the drawings are not evenly spaced.  When a ball bounces, it moves slowest at the top of the bounce, so more drawings should be around the peak of the arc and they get spaced out further and further as they reach the bottom.
The next basic principle you should familiarize yourself with is 'squash and stretch'.  This is something else the ball bounce demonstrates quite well.  Stretching an object shows an increase in speed and squashing shows a force of impact being applied to it.  For the ball bounce, the ball itself would be its standard circle at the top of the bounce.  As it goes down from the peak, it should stretch out more and more (not on a huge scale though, make the differences between the drawings fairly subtle and avoid changing the actual volume of the ball).  When the ball hits the ground, it will be squashed.  It's important to note that you shouldn't ease in to this drawing.  Less is more.  That is, less drawings between the movement and the impact creates more of an impact.  The drawings that come immediately before and after the squashed  impact drawing should be drawings of the ball fully stretched.

That covers the two most basic and important principles.  Other principles, like secondary action and the wave principle, are either more for character animation or should really have an article to themselves.  But that's not all I'm going to leave you with, we're going to take a quick look at some key terms (one of which I've already used).

Key-frames:  If you've played around in Flash, you probably understand what these are.  The key-frames should always be done first when doing the actual animation (there are a few steps that should always be done beforehand).  These are the drawings that show the main poses of the object/character.  Admittedly straight-ahead animation (in which you start at frame one and do all the frames in the order they will appear) can be more fun but will never look as good as animation done by the proper process.

Breakdown:  Similar to keys, these are simply used for less important poses and are usually, more or less, directly in between the keys.

In-betweens:  These are the remainder of the drawings that actually flesh out the animation in full.

At this point, everything else I can think of to say will just lead off into another long description, so I will leave it at that for now.