You can clone with
HTTPS or Subversion.
Official libpd website: http://libpd.cc
Official Pd community, including the Pd mailing list and "Patching Circle" meatspace community events - great places to learn about Pd and test your patches on devices: http://puredata.info/community/
Pd Anywhere community, the centralized location for discussing libpd development and patching for mobile devices, Processing, OpenFrameworks, games, and more: http://noisepages.com/groups/pd-everywhere/
Peter Brinkmann's blog: http://nettoyeur.noisepages.com/