Tutorials to animate characters in 2.5D?

I'm trying 2D character animation for game making, but it's a lot trickier than I thought. My character is broken up into dozens of separate symbols: head, arms, legs, etc. In addition, my animation requires a lot of character rotation, which means that an arm or a leg could appear behind the character's body in some frames, and then in front of the body in other frames. 

Are there any reliable tutorials for animating a 2D character that has multiple layers of foreground, middle ground, and background?