Please explain and elaborate the usage of 把, anyone?

I think the second part of ivy's answer is pretty much what you want.
I'll try to describe a little bit about what's (subconsciously) going on in a Mandarin speaker's mind when using 把.

The original meaning of 把 is "to grasp; to hold". When you grasp/hold something, very often you are handling it with activeness. Therefore, when you apply 把 to the "S 把 O V" construction, it's very much to say that "the subject handles(把) the object by doing so". The stress of the meaning is on the object and on how the object is handled, with a sense of activeness of the doer. Another thing to keep in mind is that most of the time the verb in the 把 construction is used with a suffix/adverb tagging alone. If you drop the suffix/adverb, you'll sound like a poet or a writer of old literature.

Ex: 小狗把肉吃掉了。→ The dog (小狗) handled (把) the meant (肉) (by) eating (it) up(吃掉了).
Of course a more proper English translation would be "The dog ate up the meat". However, the focus of the meaning here is not on the subject, or the dog, but on the meat and how it was handled (吃掉了), and moreover, it was the dog that wanted to do it (with activeness). If you drop the suffix/adverb of the verb, which is 掉了 in this case, it's more seen in old literature.

Because the focus of the meaning is on the object and how it's handled, the 把 construction is very often used in imperatives. When I say 把書撿起來, that means I want you to want to pick up the book (handle the book by picking it up with activeness). You'll hear tons of 把 in a cooking show to describe how the food should be prepared.

Just my two cents.