Rigs
Before reading this page you should work through the 'Animation Basics' page which explains how to animate an object that is rigid (does not have a posable skeleton or 'armature'). It's much more interesting but rather more difficult to animate a 'rig' (a character with a posable skeleton) which is the subject of this page.
A rig is a body attached to a skeleton or 'armature', ready to be set into different poses in an animation. We won’t have time to make a very sophisticated character because it is difficult to attach the ‘flesh’ to the bones such that the character behaves realistically set in different poses. So we'll use a ready-made rig.
BAKER RIG
I've chosen the Baker rig because the character is cute and has the potential to be very expressive - there are plenty of controls to control facial expressions although you will probably have time to do this only if you choose to work on this as the end-of-year project. The Baker rig was created by David Ward (no relation) for the excellent website cgcookie.com . There are plenty of free tutorials on that site but the Baker series is not free - you need to pay 9 Euros to become a 'citizen' before you can follow or download the series - it's good value though. See cgcookie.com/blender/cgc-series/character-course-animating-a-character.
Meet Baker and learn about animating him in this YouTube video (15 mins):
COOKIEFLEX
This wonderful rig allows you to adjust all kinds of properties such as clothes colors, skin color, hair style, hip size and breast size (thus male/female), muscle vs. fat, etc etc. It's all free on a Creative Commons license and downloadable HERE or HERE. You may need to become a member of Blendswap.com - membership is free and will give you access to thousands of great Blender files.
Here are links to some other rigs that you can download. Check them out!