There is a setup/install file in there some where... find and execute it after you unzip the file.
It will ask you for three different things... in the first two boxes type in
localhost in each one... the third box, type in your email address or the email address of the admin of that box.
By default it will create a directory similar to:
c:\program files\apache group\apache2\
'conf' subdirectory is where your configuration is, you can add / change what you need in the httpd.conf file. you will need to do that to establish PHP support...
'htdocs' subdirectory is where your index.html file and other publically viewable documents will be.
to test the apache installation, go to your browser and type:
http://localhost
Let me know if you have other questions.