Firestarter is an easy script to install Firefox on Debian systems

firestarter.sh

#!/bin/bash

if [ "`whoami`" != "root" ]; then
  echo "Please run this script as root"
else
  echo "Going to install latest stable Firefox, is it OK?"
  echo "Press Enter to continue or Ctrl-C to stop"

  if read; then
    echo "Adding Linux Mint repo..."
    echo "deb http://packages.linuxmint.com debian import" > /etc/apt/sources.list.d/linuxmint.list
    echo ""

    echo "Getting Linux Mint key..."
    gpg --keyserver pgp.mit.edu --recv-keys 3EE67F3D0FF405B2
    echo ""

    echo "Adding key..."
    gpg --export 3EE67F3D0FF405B2 | apt-key add -
    echo ""

    echo "Installing Firefox..."
    apt-get install firefox
    echo ""
  fi
fi