I'd suggest using autoconf or something like it eg ./configure --prefix=/my/nifty/programs

as for directory structure probably something like
/usr/local/bin/opengrade (symlink or not)
/usr/local/share/opengrade/ (data files and modules)
/usr/local/doc/opengrade-<version>/ ( Readme and such)

That is assuming you don't want to share your modules. If you do want the users to use your modules then use Makemaker and friends to install your modules wherever the local site_perl is. And use that dir structure for the rest of your files