To lubricate your treadmill you'll need to use silicone oil. A good kit to use is this:
For a good, solid guide on how to lubricate and maintain your treadmill please take a look at the video below:
Another little trick to increase the lifespan of your LunaRun is to stand on the foot rails, then start the machine and once the belt is moving then step onto it. This reduces the strain on the drive motor as it's not trying to move a dead weight the same as when you're standing on the belt when it's stationary and trying to get moving.
One last thing - once a year unplug the treadmill from the mains and remove the plastic motor cover at the front of the machine. Use a vacuum cleaner to vacuum up any dust that's inside. Between this, standing on the rails until the belt is already moving and proper lubrication you will add years to the life of the treadmill.