Added info about installation

Debian.md

@@ -1,8 +1,28 @@
 Offical ZFS on Linux [DKMS][dkms] style packages are available from the [Debian GNU/Linux repository](https://tracker.debian.org/pkg/zfs-linux) for the following configurations.  The packages previously hosted at archive.zfsonlinux.org will not be updated and are not recommended for new installations.
 
-**Debian Releases:** Sid (Eternal unstable)  
+**Debian Releases:** Jessie and newer (testing, sid)  
 **Architectures:** amd64  
 
+## Installation
+For Debian Jessie, ZFS packages are provided by [backports](https://backports.debian.org/Instructions/).
+
+Add jessie-backports  repository (ZFS packages are in `contrib` area):
+
+	# echo "deb http://ftp.debian.org/debian jessie-backports main contrib" >> /etc/apt/sources.list.d/backports.list
+	# apt update
+
+Install kernel headers:
+
+	# apt install linux-headers-$(uname -r)
+
+Install zfs packages:
+
+	# apt-get install -t jessie-backports zfs-dkms
+
+If you want to boot from ZFS, you'll need `zfs-initramfs` package too:
+
+	# apt-get install -t jessie-backports zfs-initramfs
+
 [dkms]: https://en.wikipedia.org/wiki/Dynamic_Kernel_Module_Support
 [debian-announce]: https://lists.debian.org/debian-devel-announce/2015/04/msg00006.html
 [debian-itp]: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=686447