Unfortunately writing a library exposes you to a bit more C++ than writing a sketch. A good starting point is an existing library - have a look at several and you'll soon get a feel for the form of things.
Did you put the contents of Morse.zip in the right place (The Morse directory inside your libraries directory)?
I've had a look at Morse.zip - its not yet 1.0 compatible - just change
#include "WProgram.h"
to
#if defined(ARDUINO) && ARDUINO >= 100
#include "Arduino.h"
#else
#include "WProgram.h"
#endif
in the .h and .cpp files