This is coming from experience, not a book  

I find that stretching your legs is very important.  I usually stand and separate them very far and then lean to the left and right (bending one leg, keeping the other one straight) to loosen the muscles.  This helps greatly with the muscles in the back of your thigh.  You can feel the effect it has.  

I will also sit and pick up one foot and rotate my ankle, this helps both my calf muscle and whatever muscle it is than runs from your shin (I'd look up all the muscle groups, but hopefully you understand which ones I'm talking about   )  

I'll also generally exercise my back muscles by standing straight, leaving my feet planted, and gently turning the torso from left to right and back again.  I can have problems with this because I have a "trick" back that can go out if I'm not careful.

I even exercise my neck simply by doing head rotations.  This helps me loosen up very tight neck muscles that probably come from sitting in front of a computer all day.

I didn't always do a stretching routine before I played.  I think as I'm aging, the stretching exercises become more important for a really comfortable playing experience.  

But that's not to say you shouldn't start now, warming up your muscles (especially ones you know you'll be working) before any physical activity is simply a good idea.

IMHO, you should stretch all of your legs.  they all work in tandem with one another.

besides the usual calf and quad stretches, i do a particular one that really stretches out the muscles of my shins for Heeldown work.

Standing straight with your feet close together, you're going to bend over and touch your toes, while keeping your knees straight.

but instead of your legs side to side, you're gonna cross one leg over the other, and place the opposing foot, perfectly side to side with the other foot.  

bend over and stretch, making sure the leg that's not crossed is straight.  after a 12 count, swtich the crossed legs, and repeat for 3 sets.