How to include Info manuals in packages?

[Mariano Montone]

Hello,

I'm considering adding a manual an Info format to my package. My package 
is installable from ELPA.

I have these questions:

1) Is it good practice to include an Info manual in same package that 
contains the package source code?

2) How to get the Info manual installed when the user installs my package?


Thank you,

      Mariano