The enchantment is based on your skill level, so 1 enchanting skill level = 1% or 1pt. Most magic effects have atleast 2(sometimes more) MGEF IDs, one is usually the actual effect while the other is used by magic tomes to teach you spells. The second type will teach you the spell, and may use the visual spell effects(ex: candlelight will show the glowing orb of light but it won't actually provide light).
Usually the first instance is the actual effect, but save before using it in case your using the wrong one.
This command can't be used to modify existing objects(like additem, but with 1-2 enchantments) and it doesn't work on pre-enchanted apparel/weapons, including any unique gear. It will give you the item, but it will still have it's original enchantments.
I'm not sure how the charges get calculated for weapons when using the console command.