Get NetworkManager working after suspend

After going into standby mode ("suspend") or hibernation, NetworkManager might refuse to connect to your network of choice. The trick is to restart NetworkManager after standby. You will need to create two files.
suspend.d/07-network-manager.sh

sudo touch /etc/acpi/suspend.d/07-network-manager.sh
gksudo gedit /etc/acpi/suspend.d/07-network-manager.sh

Now paste the following in Gedit, save and close.

#!/bin/sh
/etc/dbus-1/event.d/25NetworkManager stop

resume.d/63-network-manager.sh

sudo touch /etc/acpi/resume.d/63-network-manager.sh
gksudo gedit /etc/acpi/resume.d/63-network-manager.sh

Now paste the following in Gedit, save and close.

#!/bin/sh
/etc/dbus-1/event.d/25NetworkManager start

Links of Interest
Ubuntu wiki's NetworkManager page