Understanding the contents of a library in C
What I have always wanted to know is: where can you find the "instruction set", inc C, for these libraries?


The libraries are usually found in the libraries sub-folder under your sketchbook folder (wherever that is). There is also another libraries folder inside the IDE install folder for the "official libraries".


  How can I find out what commands are available for me to use with this library?


Usually the library documents them in one way or another. Try looking inside the .h file used by the library to see what functions are exposed.