tjkanavel,
Things like trigger jobs and hanger bars benefit the true handgun afficianados--people who shoot competition or hunt regularly with a handgun. If you are a novice, more than likely such improvements will not benefit your skill level. So the first thing to ask yourself, do you really need these upgrades? I have done neither to my Encore, and still get acceptable accuracy out to several hundred yards.
That being said, a "hanger bar" is one method of floating the barrel from the forestock to reduce pressure on your barrel. This is primarily a concern when you are shooting a lot. When your barrel heats up, it tends to flex some. This is more common in tapered barrels where you get uneven heat dissipation between the thicker and thinner parts of the barrel. The reason you float the barrel is that as the barrel flexes as it warms, any part of the stock touching the barrel will put pressure on it, potentially spoiling your accuracy.
One way of floating the barrel is to take a hanger bar (there are a couple companies that make them--such as Bulberry or Ole Georgia Jim) and attach it to the bottom of the barrel. Your forestock is routered out for the bar, which essentially acts as a spacer between forestock and barrel.
The cheap way to do this, particularly if you don't want to go through the expense of the hanger bar and changing your forestock, or paying for one specially made, is to place a couple of rubber washers between the barrel and forestock over the forestock's mounting screws. You may want to try this before buying the hanger bar.
