Today before my CCNA lecturer end the class, he presented us with a very interesting video about how packets being delivered from your computer to the server and go back to your computer. It is very informative video and the video title is The Dawn of the Net.
I found the video in Youtube divided into two parts. You can watch and learn what happens in the process of delivering the packets and receive it.
I think all who take CCNA course will be presenting with this video. This video is really helpful for you to understand the basic concept on how the TCP/IP works.