So we can agree that hormones can bring about many changes within living organisms. One of the main processes that hormones control in animals (incuding humans) is that of puberty. Watch these videos on changes that occur during puberty:

Infographics: Puberty

You will find more information in the video links below:

What is puberty?
Puberty in males
Puberty in females
Though filmed in 1953, the video below by McGraw Hill provides specific biological information.
Puberty- The Basics

The process is followed in this Discovery Channel video:

Discovery channel link:
Discovery channel: teen dreams

It is important to understand that these systems only become active once puberty has been completed. The process of puberty depends on hormonal changes within the body. It is not a quick process, boys do not suddenly become muscular powerhouses.....

Instead the changes are more gradual. It is understandable that you may have a number of questions that you may not wish to discuss, have a look at this series of videos from the HOWCAST team which provide some information for you:
How to survive puberty series