echo $PATH should return the path on your machine.
/usr/bin is probably the best place to put the program, you can use /bin or /sbin but these should be reserved for system programs and can be wiped during system upgrade (unix standards not apples).
To run a program in your current diectory you should type ./programname to run it and you should try this before you copy a program into any directory in your path.
Gaz
