Okay, first, please tell me if this is the right forum to post this question, 'cause I'm new to LinuxQuestions.org, and I don't know much about how it works.
If this is the right forum however, here is my situation:
First of all, I'm a Windows user, so I'm not familiar at all with Ubuntu. Yet, I want to use a computer running Ubuntu as a test server to learn how to use PHP, MySQL and Apache. I bought a book on these three programs, but the installation directives were for more advanced Linux users, and I didn't understand them. So can anyone help me?

P.S: If this is the wrong forum, please direct me to the correct one.

What your looking for is this article, It will go step by step and guide you through the whole thing.

Regards,
JKZfixme

These should certainly help you out:

https://help.ubuntu.com/community/ApacheMySQLPHP
http://www.howtoforge.com/ubuntu_lamp_for_newbies

Thank you, this is just what I needed!

Well, nice to know. Wishing you good luck in your endeavor to convert Ubuntu into a LAMP system.