The web site for QUANTUM ESPRESSO is http://www.quantum-espresso.org/. Releases and patches can be downloaded from this site or following the links contained in it. The main entry point for developers is the QE-forge web site: http://www.qe-forge.org/.
Announcements about new versions of QUANTUM ESPRESSO are available via a low-traffic mailing list Pw_users: pw_users@pwscf.org. You can subscribe (but not post) to this list from the QUANTUM ESPRESSO web site.
The recommended place where to ask questions about installation and usage of QUANTUM ESPRESSO, and to report bugs, is the Pw_forum mailing list: pw_forum@pwscf.org. Here you can obtain help from the developers and many knowledgeable users. You can browse and search its archive from the QUANTUM ESPRESSO web site, but you have to subscribe in order to post to the list. Please search the archives - using the search facility, accessible from the web site, or using google - before posting: many questions are asked over and over again.
Important notice: only messages that appear to come from the registered user's e-mail address, in its exact form, will be accepted. Messages "waiting for moderator approval" are automatically deleted with no further processing (sorry, too much spam). In case of trouble, carefully check that your return e-mail is the correct one (i.e. the one you used to subscribe).
The Pw_forum mailing list is also the recommanded place where to contact the developers of QUANTUM ESPRESSO.