I am a GIS hobbyist but quite new to Linux.
Debian used to be my favourite distro long time ago so I was happy to find your distro debian-live-8.5.0-amd64-gis.iso
Installation was easy and it runs in the VirtualBox o.k.
I joinned Debian forum to search for advice and help.
vladiangis@Debian-gis:~$ sudo apt-get update
Ign cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20160613-13:58] jessie InRelease
Ign cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20160613-13:58] jessie Release.gpg
Ign cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20160613-13:58] jessie Release
Ign cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20160613-13:58] jessie/main amd64 Packages/DiffIndex
Ign cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20160613-13:58] jessie/main Translation-en_GB
Ign cdrom://[Debian GNU/Linux 8 _Jessie_ - Official Snapshot amd64 LIVE/INSTALL Binary 20160613-13:58] jessie/main Translation-en
Hit http://security.debian.org jessie/updates InRelease
Hit http://security.debian.org jessie/updates/main Sources
Hit http://security.debian.org jessie/updates/main amd64 Packages
Hit http://security.debian.org jessie/updates/main Translation-en
Reading package lists... Done
W: There is no public key available for the following key IDs:
AA8E81B4331F7F50
Your help would be appreciated.