(If your machine has a top loading bobbin, you can view my tutorial HERE on how to properly load that type of bobbin into your machine.)
First, take your bobbin and hold it like the letter "b". See how the thread is coming off from it in the picture below?
Next, insert it into the metal bobbin case while still holding out a tail of thread.
Insert the thread tail into the small notch on the metal bobbin case.
Pull the thread tail under the bobbin tension plate until it comes out through this hole (you will hear a little click when it come through that hole).
TIP: You know that you have threaded the bobbin correctly if when you pull the thread, the bobbin spins clockwise when looking at it.
Next, holding the bobbin in the metal case, open up the hinged arm in the front of the metal bobbin case.
Insert the metal bobbin case (while holding the hinged arm out) into the machine so that the hook at the top of the case fits into the notch (located in the 12 o'clock position) in your machine.
Now let go of the hinged arm and this will lock the bobbin into place. You can try to pull on the bobbin case but it should not budge in any direction or fall out.
This is how it should look in place.
Now pull the thread the tail out and close the door to your bobbin case area and laid your thread on top of your machine. You have now correctly loaded your front loading bobbin! Now you are ready to draw up your bobbin thread with your top thread and you can refer to my tutorial on "How to thread your sewing machine" for guidance on how to do that.