I object! Or is that object?

Let's go back to grammar school for a minute and revisit the Subject and Object. Don't worry--this is a quick and easy lesson!
The subject is the main player in the sentence. The leading actor. The person (or thing) without whom the sentence would not be able to function. For instance, check out the following sentence:
Maude picked up the books.
Maude IS the subject. Without Maude, there would be no books being picked up. They would stay on the table, or wherever they were.

The object of the sentence is having something done to it. Without the object, the subject would just be standing there, mid-stage, an actor without a prop. In the previous sentence the books would be the object, since they are having something done to them (they are being picked up).

Simple, right? In theory, yes. But when the sentences get long and convoluted, sometimes it is more difficult to parse out the noun and the subject. And, quite frankly, unless you are an editor or an elementary school teacher, generally you don't NEED to. Even then, the need is sketchy. When this becomes important is when you are writing. You should always know where your subject and object are.
It's nine o'clock. Do you know where your subject is? (Why yes, I am operating on little sleep today--why do you ask?)

So, there was my brief covering of subject and object. They are important to know when constructing sentences--they the foundation upon which the sentence is built. Well, the subject, object and verb, but we'll talk about verbs tomorrow.