Do i Build Blender for every change I make in the code? I want to see how the BVH import script in blender works.

I was thinking if i could print the values of the variables at different points in the code to the console then it would help me a lot.(just like the logs printed in Report Console in blender)

Will i have to build Blender everytime i make a change in the code ?

And what does build exactly mean ? (if it is not something similar to what the commands  "gcc -o testOut test.c"  does to a C file)

Any References, Documents, Links would help.

Thanks.
No you don't.

The BVH import addon is a python script. You should be able to disable/enable the addon after you make changes so that blender reloads the scripts. At most you may need to restart blender.