Within ppm4 (the gui interface), you can add repositories by selecting Edit -> Preferences -> Repositories, and then adding the corresponding location (and a name you want to remember it by). A couple of ones you might want to add that have some popular packages not present in ActiveState's (extensive) repository are http://www.bribes.org/perl/ppm and http://theoryx5.uwinnipeg.ca/ppms/. The Crypt-SSLeay package is in the uwinnipeg repository, but this contains a post-install script to download and install the necessary openssl dlls, and the current ppm4 gui doesn't handle post-install scripts. What you can do is add these respositories, quit the gui, and then run

 C:\> ppm install Crypt-SSLeay
[download]

from a console window.