Packages are not my area of expertise.
At first your package is ".m" file or more ".m" files. (may include additional data or documentation)
See link:
http://stackoverflow.com/questions/4641512/how-to-install-new-packages-for-mathematica
There is written:
Packages are placed on $UserBaseDirectory/Applications or $BaseDirectory/Applications.
If you want more comfort and your own documentations and more features, so you need install Wolfram Workbench.
My answer is blunt, because I do not know all the details and describe them takes many times.
