There really isn't anything to making a library, just put a bunch of files a a certain directory and there you go.
If you are taking about writing your code in c and compiling it to be an actually .so or .dll file... thats another story.
My "library" is a directory called lib with sub directories such as html, data, io, util, etc where I put the common classes i create in appropriate subdirectories so they are easy to find.
