There really isn't that much to it, just tying a brush to the entity and setting a few attributes as neccessary.
The most commonly changed attributes are
Strength, which determines the ammount of damage the object takes before it breaks,
Material type, which sets the gibs that will spawn when the object is destroyed, and
Explode magnitude, which determines the size of the explosion the object creates when it breaks (the higher the number, the bigger the blast, 0 for no explosion).
There are a few more attributes and some flags, just mess around with them and see what they do.